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Debugging with -d
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37.5 Reference in Numerical Order

The sendmail debugging switches vary from vendor to vendor and from version to version. This section is specific to V8.8.0 sendmail. These switches are perhaps best used with a copy of the sendmail source by your side. Be further advised that many of the internal details shown here will change as sendmail continues to evolve and improve.

In this section we provide a detailed description of each combination of debugging category and level. In Table 37.2 each debugging category and level that we consider useful for the system administrator who is trying to solve a mail problem is marked with "useful." The others provide such complex and sophisticated output that they may be of use only to those with access to the source. Those marked in the section column with a "n/a" are debugging switches that were introduced in the sendmail source too late for documentation in this edition. All are presented in ascending numerical order, first by category, then by level within each category.

Note that for all categories a -dcategory and a -dcategory.1 are always equivalent.

Table 37.2: Debugging Switches by Category
CategoryIt isDescription
-d0.1Section 37.5.1, -d0.1useful

Print version information

-d0.4Section 37.5.2, -d0.4useful

Our name and aliases

-d0.10Section 37.5.3, -d0.10

Operating System defines

-d0.15Section 37.5.4, -d0.15useful

Dump delivery agents

-d0.20Section 37.5.5, -d0.20useful

Print network address of each interface

-d0.22Section 37.5.6, -d0.22

Show uname() failure

-d0.40Section 37.5.7, -d0.40

Show scanning of interfaces

-d0.44Section 37.5.8, -d0.44

Print addresses of strings

-d0.90Section 37.5.9, -d0.90obsolete

Print first 10 rule sets

-d1.1Section 37.5.10, -d1.1

Show sender information

-d1.5Section 37.5.11, -d1.5

Dump the sender address

-d2.1Section 37.5.12, -d2.1

End with finis()

-d2.9Section 37.5.13, -d2.9

Show file descriptors with dumpfd()

-d3.1Section 37.5.14, -d3.1

Print the load average

-d3.5Section 37.5.15, -d3.5

Print load average

-d3.15Section 37.5.16, -d3.15

Print three load averages

-d3.20Section 37.5.17, -d3.20

Show offset for load average

-d3.30Section 37.5.18, -d3.30

Show result of decision to queue

-d4.80Section 37.5.19, -d4.80useful

Trace enoughspace()

-d5.4Section 37.5.20, -d5.4

Tick for queued events

-d5.5Section 37.5.21, -d5.5

Events set and cleared

-d5.6Section 37.5.22, -d5.6

Show events triggered

-d6.1Section 37.5.23, -d6.1useful

Show failed mail

-d6.5Section 37.5.24, -d6.5

The current error state

-d6.20Section 37.5.25, -d6.20

Show sender of return to sender

-d7.1Section 37.5.26, -d7.1

The Queue filename

-d7.2Section 37.5.27, -d7.2

Show assigned queue filename

-d7.9Section 37.5.28, -d7.9

Dump file descriptor for the qf file

-d7.20Section 37.5.29, -d7.20

Show queue names being tried

-d8.1Section 37.5.30, -d8.1useful

Failure of MX search (low level)

-d8.2Section 37.5.31, -d8.2useful

Call to getcanonname(3)

-d8.3Section 37.5.32, -d8.3useful

Trace dropped local hostnames

-d8.5Section 37.5.33, -d8.5useful

Hostname being tried in getcanonname(3)

-d8.7Section 37.5.34, -d8.7 useful

Yes/no response to -d8.5

-d8.8Section 37.5.35, -d8.8useful

MX lookup gets wrong type

-d8.20Section 37.5.36, -d8.20

Inconsistency in returned information

-d9.1Section 37.5.37, -d9.1

Canonify hostname and RFC1413 queries

-d9.3Section 37.5.38, -d9.3

Show raw RFC1413 reply

-d9.10Section 37.5.39, -d9.10

Show RFC1413 query being sent

-d10.1Section 37.5.40, -d10.1

Show recipient delivery

-d10.2Section 37.5.41, -d10.2

Dump controlling user's address

-d10.5Section 37.5.42, -d10.5

Show don't send to MeToo address

-d10.100Section 37.5.43, -d10.100

Predelivery file descriptor dump

-d11.1Section 37.5.44, -d11.1useful

Trace delivery

-d11.2Section 37.5.45, -d11.2useful

Show the uid/gid running as during delivery

-d11.20Section 37.5.46, -d11.20

Show tried D= directories

-d12.1Section 37.5.47, -d12.1useful

Show mapping of relative host

-d13.1Section 37.5.48, -d13.1useful

Show delivery

-d13.5Section 37.5.49, -d13.5

Show addresses that we should not send to

-d13.6n/a

Trace envelope stripping, dropping, and moving

-d13.10Section 37.5.50, -d13.10

Trace sendenvelope()

-d13.20Section 37.5.51, -d13.20

Show final mode

-d13.21n/a

Show final send queue

-d13.25n/a

Watch owner deliveries

-d13.29Section 37.5.52, -d13.29

Show autoqueueing

-d13.30Section 37.5.53, -d13.30

Show envelopes being split

-d14.2Section 37.5.54, -d14.2

Show header field commas

-d15.1Section 37.5.55, -d15.1

Show network get request activity

-d15.2Section 37.5.55

Incoming connections

-d15.101Section 37.5.57, -d15.101

Kernel TCP debugging

-d16.1Section 37.5.58, -d16.1

Outgoing Connections

-d16.101Section 37.5.59, -d16.101

Kernel TCP debugging

-d17.1Section 37.5.60, -d17.1

List MX hosts

-d17.9Section 37.5.61, -d17.9

Show randomizing MX records

-d18.1Section 37.5.62, -d18.1

Show SMTP replies

-d18.2Section 37.5.63, -d18.2

Show entry to MAIL From:

-d18.100Section 37.5.64, -d18.100

Pause on SMTP read error

-d19.1Section 37.5.65, -d19.1

Show ESMTP MAIL and RCPT parameters

-d20.1Section 37.5.66, -d20.1useful

Show resolving delivery agent: parseaddr()

-d21.1Section 37.5.67, -d21.1

Trace rewriting rules

-d21.2Section 37.5.68, -d21.2useful

Trace $& macros

-d21.3Section 37.5.69, -d21.3

Show subroutine calls

-d21.4Section 37.5.70, -d21.4

Result after rewriting by a rule

-d21.10Section 37.5.71, -d21.10

Announce failure

-d21.12Section 37.5.72, -d21.12

Announce success and show LHS

-d21.15Section 37.5.73, -d21.15

Show $digit replacement

-d21.35Section 37.5.74, -d21.35

Show token by token LHS matching

-d21.36Section 37.5.75, -d21.36

Trace class matching in the LHS

-d22.1Section 37.5.76, -d22.1useful

Trace tokenizing an address: prescan()

-d22.11Section 37.5.77, -d22.11useful

Show address before prescan

-d22.12Section 37.5.78, -d22.12

Show address after prescan

-d22.36Section 37.5.79, -d22.36

Show each token

-d22.101Section 37.5.80, -d22.101

Trace low-level state machine

-d24.4Section 37.5.81, -d24.4

Trace address allocation

-d24.5Section 37.5.82, -d24.5

Trace assembly of tokens

-d24.6Section 37.5.83, -d24.6

Show result of buildaddr()

-d25.1Section 37.5.84, -d25.1usefulTrace "sendtolist"
-d26.1Section 37.5.85, -d26.1Trace recipient queueing
-d26.8Section 37.5.86, -d26.8Trace self-destructing addresses
-d26.10Section 37.5.87, -d26.10Show full send queue in testselfdestruct
-d27.1Section 37.5.88, -d27.1usefulTrace aliasing
-d27.2Section 37.5.89, -d27.2usefulInclude file, self-reference, error on home
-d27.3Section 37.5.90, -d27.3usefulForwarding path and alias wait
-d27.4Section 37.5.91, -d27.4usefulPrint not safe
-d27.5Section 37.5.92, -d27.5Trace aliasing with printaddr()
-d27.8Section 37.5.93, -d27.8Show setting up an alias map
-d27.9Section 37.5.94, -d27.9usefulShow uid/gid changes with :include: reads
-d27.14Section 37.5.95, -d27.14Show controlling user that caused change in identity
-d27.20Section 37.5.96, -d27.20Show how alias will be looked up in a map
-d28.1Section 37.5.97, -d28.1usefulTrace user database transactions
-d28.2Section 37.5.98, -d28.2Show no match
-d28.4Section 37.5.99, -d28.4Show result of lookup
-d28.8Section 37.5.100, -d28.8Try hes_getmailhost()
-d28.16Section 37.5.101, -d28.16MX records for forward host
-d28.20Section 37.5.102, -d28.20Show udb lookup
-d28.80Section 37.5.103, -d28.80Preview lookups
-d29.1Section 37.5.104, -d29.1Special rewrite of local recipient
-d29.4Section 37.5.105, -d29.4usefulTrace fuzzy matching
-d29.5Section 37.5.106, -d29.5Preview rule set 5
-d29.7Section 37.5.107, -d29.7Show overaliasing fuzzy fallback
-d30.1Section 37.5.108, -d30Trace processing of header
-d30.2Section 37.5.109, -d30.2Eat from
-d30.3Section 37.5.110, -d30.3Show a to-less header being added
-d30.35Section 37.5.111, -d30.35Trace collect states
-d30.94Section 37.5.112, -d30.94Trace collect states
-d31.2Section 37.5.113, -d31.2usefulTrace processing of headers
-d31.6Section 37.5.141_6Is header known?
-d32.1Section 37.5.115, -d32.1Show collected headers
-d32.2Section 37.5.116, -d32.2Show ARPA mode with setsender
-d33.1Section 37.5.117, -d33.1Watch crackaddr()
-d34.1Section 37.5.118, -d34.1Watch header assembly for output
-d34.11Section 37.5.119, -d34.11usefulTrace header generation and skipping
-d35.9Section 37.5.120, -d35.9usefulMacro values defined
-d35.14Section 37.5.121, -d35.14Macro identification
-d35.24Section 37.5.122, -d35.24Macro expansion
-d36.5Section 37.5.123, -d36.5Trace processing by stab()
-d36.9Section 37.5.124, -d36.9Show hash bucket
-d36.90Section 37.5.125, -d36.90Trace function applied to all symbols
-d37.1Section 37.5.126, -d37.1usefulTrace setting of options
-d37.8Section 37.5.127, -d37.8usefulTrace adding of words to a class
-d38.2Section 37.5.128, -d38.2usefulShow map opens and failures
-d38.3Section 37.5.129, -d38.3Show passes
-d38.4Section 37.5.130, -d38.4usefulShow result of map open
-d38.9Section 37.5.131, -d38.9Trace map closings and appends
-d38.10Section 37.5.132, -d38.10Trace NIS search for end of aliases
-d38.12Section 37.5.133, -d38.12Trace map stores
-d38.19Section 37.5.134, -d38.19usefulTrace switch map finds
-d38.20Section 37.5.135, -d38.20usefulTrace map lookups
-d38.44Section 37.5.136, -d38.44Show nis_getcanonname() record
-d39.1Section 37.5.137, -d39.1Display %digit database mapping
-d40.1Section 37.5.138, -d40.1Trace processing of the queue
-d40.3Section 37.5.139, -d40.3Show envelope flags
-d40.4Section 37.5.140, -d40.4Show qf file lines as they are read
-d40.8Section 37.5.141, -d40.8Show reasons for failure
-d40.9Section 37.5.142, -d40.9Show qf and lock file descriptors
-d40.32Section 37.5.143, -d40.32Dump the send queue
-d41.1Section 37.5.144, -d41.1usefulTrace queue ordering
-d41.2Section 37.5.145, -d41.2Cannot open qf
-d41.49Section 37.5.146, -d41.49Show excluded (skipped) queue files
-d41.50Section 37.5.147, -d41.50Show every file in the queue
-d42.2Section 37.5.148, -d42.2Show connection checking
-d42.5Section 37.5.149, -d42.5Trace caching and uncaching connections
-d43.1Section 37.5.150, -d43.1Trace MIME conversions
-d43.3Section 37.5.151, -d43.3See the final MIME boundary name
-d43.5Section 37.5.152, -d43.5Watch search for boundaries
-d43.8Section 37.5.153, -d43.8Show the calculations
-d43.35Section 37.5.154, -d43.35Show boundary lines as emitted
-d43.36Section 37.5.155, -d43.36Show content transfer encoding
-d43.40Section 37.5.156, -d43.40Show parse of Content-Type: header
-d43.99Section 37.5.157, -d43.99Print the leading/following comments
-d43.100Section 37.5.158, -d43.100Mark collect() and putheader()
-d44.4Section 37.5.159, -d44.4Trace safefile()
-d44.5Section 37.5.160, -d44.5usefulTrace writable()
-d45.1Section 37.5.161, -d45.1Show envelope sender
-d45.3Section 37.5.162, -d45.3Show saved domain
-d45.5Section 37.5.163, -d45.5Show don't send to sender
-d46.9Section 37.5.164, -d46.9Show xf file's descriptors
-d48.2Section 37.5.165, -d48.2usefulTrace calls to the check_ rule sets
-d49.1Section 37.5.166, -d49.1Trace checkcompat()
-d50.1Section 37.5.167, -d50.1Show envelope being dropped
-d50.2Section 37.5.168, -d50.2Show Booleans
-d50.10Section 37.5.169, -d50.10Also show the send queue
-d51.4Section 37.5.170, -d51.4Show queue entries being unlocked
-d51.104Section 37.5.171, -d51.104Prevent unlink of xf file
-d52.1Section 37.5.172, -d52.1Show isconnect from controlling TTY
-d52.100Section 37.5.173, -d52.100Prevent disconnect from controlling tty
-d53.99Section 37.5.174, -d53.99Trace xclose()
-d54.1Section 37.5.175, -d54.1Show error return and output message
-d54.8Section 37.5.176, -d54.8Show message and flags
-d55.60Section 37.5.177, -d55.60Show file locking
-d56.1Section 37.5.178, -d56.1Persistent host status tracing
-d56.2Section 37.5.179, -d56.2More persistent host status tracing
-d56.12Section 37.5.180, -d56.12Perform a sanity check
-d56.80Section 37.5.181, -d56.80Trace creating the path to the status file
-d56.93Section 37.5.182, -d56.93Dump MCI record for the host
-d57.2Section 37.5.183, -d57.2Monitor vsnprintf() overflows
-d59.1Section 37.5.184, -d59XLA from contrib
-d60.1Section 37.5.185, -d60.1usefulTrace map lookups inside rewrite()
-d61.10Section 37.5.186, -d61.10Trace gethostbyname()
-d62.1Section 37.5.187, -d62.1Log file descriptors before and after all deliveries
-d62.8Section 37.5.188, -d62.8Log file descriptors before each delivery
-d62.10Section 37.5.189, -d62.10Log file descriptors after each delivery
-d80.1Section 37.5.190, -d80.1Content-Length: header (Sun enhancement)
-d81.1Section 37.5.191, -d81.1> option for remote mode (Sun enhancement)
-d91.100Section 37.5.192, -d91.100Log caching and uncaching connections
-d99.100Section 37.5.193, -d99.100usefulPrevent backgrounding the daemon

37.5.1 -d0.1

Print version information

(useful)

The -d0.1 (a.k.a. -d0) debugging switch previously prevented sendmail from forking and detaching itself, but that function has been moved to the -d99.100 debugging switch. The -d0.1 debugging switch now just tells sendmail to print information about its version:

Version 8.8.4
Compiled with:   LOG MATCHGECOS NAMED_BIND NDBM NEWDB NETINET NETUNIX
                 NIS
SYSTEM IDENTITY (after readcf):
            (short domain name) $w = here
        (canonical domain name) $j = here.US.EDU
               (subdomain name) $m = US.EDU
                    (node name) $k = here

The Version is the current version of sendmail. Note that for Sun the number may look like SMI-8.7.5.

The Compiled with: lists the compile-time definitions that where specified when sendmail is compiled. All the available definitions are listed in Table 18.3 in Section 18.8, "Alphabetized Reference".

The SYSTEM IDENTITY shows the value assigned to four important macros. The meaning of each macro is contained in Table 31.7 in Section 31.10, "Alphabetized Reference".

37.5.2 -d0.4

Our name and aliases

(useful)

The -d0.4 debugging switch tells sendmail to print several additional lines of information:

Version 8.8.4
Compiled with:   LOG MATCHGECOS NAMED_BIND NDBM NEWDB NETINET NETUNIX
                 NIS
canonical name: here.US.EDU                           <- additional
 UUCP nodename: here                                  <- additional
        a.k.a.: [123.45.67.89]                        <- additional
============ SYSTEM IDENTITY (after readcf) ============
            (short domain name) $w = here
        (canonical domain name) $j = here.US.EDU
               (subdomain name) $m = US.EDU
                    (node name) $k = here
========================================================

To find the canonical name of the local host, sendmail calls gethostname(). If that call fails, the name localhost is used. The hostname is then looked up with the internal routine sm_gethostbyname(), which gathers additional information (such as other names and addresses for the machine) and fixes several bugs in some operating system's versions of the gethostby... routines. Next the canonical name for the local host is looked up. For operating systems that normally support switched services, the name is looked up as specified. For systems that specify switched services in the configuration file's ServiceSwitchFile option (see Section 34.8.61, ServiceSwitchFile), switched services are not used because the configuration file has not been read yet. (This canonicalization process can be traced with the -61.10 debugging switch.) If the canonical is found and that name contains a dot, sendmail saves the part of the name to the right of the leftmost dot as the domain name in the $m macro (see Section 31.10.24, $m). It also appends the part of the name to the left of the leftmost dot to the class w (see Section 32.5.8, $=w). If the canonical name doesn't contain a dot, the $m macro is undefined, and the whole name is appended to the class w.

In addition, sendmail also sets the $k macro (see Section 31.10.21, $k) to be the correct UUCP name for the machine. It uses uname(3), if available, to find that name (see Section 18.8.51, TRUST-POPEN); otherwise, it uses the same strategy as for class w above.

Then sendmail lists any other names or addresses (this latter in square brackets) that it found. If it finds any, it prints the name prefixed by a.k.a.: and appends each to the class w. The aliases listed are only those found using gethostbyname(3). To see each entry as it is added to the class w, use the -d37.8 debugging switch.

Finally, sendmail scans the network hardware to find any other names associated with interfaces. If the ioctl(2) call to get that information fails, the -d0.4 debugging switch causes sendmail to print that failure:

SIOGIFCONF failed: <- reason here

If any are found, each is printed with an a.k.a.: prefix and added to the class macro w.

37.5.3 -d0.10

Operating System Defines

The -d0.10 debugging switch causes sendmail to print all the operating system specific definitions that were used to compile your specific version of sendmail. This output prints after the "Compiled with:" information described above:

OS Defines: HASFLOCK HASGETUSERSHELL HASINITGROUPS HASLSTAT
                HASSETREUID HASSETSID HASSETVBUF HASUNAME IDENTPROTO
                IP_SRCROUTE
Kernel symbols: /vmunix
   Config file: /etc/sendmail.cf
  Proc Id file: /etc/sendmail.pid

The OS Defines are described in Table 18.3 in Section 18.8. Most are automatically determined during compilation; others are specified in Makefile.

The Kernel symbols is the name of file that is accessed to determine the load average. It is automatically defined correctly when conf.c is compiled. The location of the configuration file and the process identifier file are defined in the Makefile and conf.h in the sendmail source (see Section 18.8.34, PATH...).

37.5.4 -d0.15

Dump delivery agents

(useful)

The -d0.15 debugging switch causes sendmail to display how it interpreted its delivery agent definitions. The clarity and completeness of the delivery agent information vary with the version of sendmail. See the =M rule-testing command (Section 38.4.2, "Show Delivery Agents with =M") for an example of this output.

37.5.5 -d0.20

Print network address of each interface

(useful)

When sendmail scans the network hardware to find other names for the local host, it uses only those names that are new. Each new name was printed by the -d0.4 debugging switch above. To see every name that sendmail finds, new and old alike, use the -d0.20 debugging switch:

128.32.201.55                                       <- already found
127.0.0.1                                           <- found new
        a.k.a.: [127.0.0.1]

37.5.6 -d0.22

Show uname() failure

Ordinarily, if the UUCP name for the local host cannot be found (if uname(3) fails), sendmail silently uses the leftmost component of the canonical name as the UUCP name. To see whether uname(3) failed - and, if so why - you can use the -d0.22 debugging switch:

uname failed (reason for failure here)

37.5.7 -d0.40

Announce scanning of interfaces

The -d0.40 debugging switch causes sendmail to announce that it is about to scan for network interfaces:

scanning for interface specific names, ifc_len=64
        a.k.a.: [127.0.0.1]

The ifc_len is the size in bytes of the configuration list returned by the kernel.

37.5.8 -d0.44

Print addresses of strings

The -d0.44 debugging switch causes sendmail to prefix certain lists of strings that it prints with the address in memory of each string and an equal sign. With this debugging level, part of the output produced by the -d21.12 debugging switch would look like this:

--- rule fails
---trying rule:
        0009ec68=@
        0009ec78=$*
--- rule fails

This debugging level can be useful to the programmer who wishes to modify the sendmail source. It might, for example, be helpful in designing more efficient string storage.

37.5.9 -d0.90

Print first 10 rule sets

(obsolete)

The -d0.90 debugging switch causes sendmail to display its internal interpretations of the first 10 rewriting rules it took from the configuration file. The rule sets are printed in numeric order, rather than in the order in which they appeared in the configuration file. The rewriting rules are printed under each rule set (but these are in the order in which they appeared in the configuration file). Rule sets that are declared but lack rewriting rules are not printed. Note that defined macros in the RHS are expanded (the value used) when the configuration file is parsed. Also note that expressions like $+ may be printed as control characters (e.g., ^A) under older versions of sendmail.

The preferred way to view individual rule sets is with the -bt rule-testing mode's =S command (see Section 38.4.1, "Show Rules in a Rule Set with =S").

37.5.10 -d1.1

Show sender information

Although there are many kinds of information that one might like to trace about the sender of an email message, sendmail provides the means to trace only one of them. The -d1.1 (a.k.a. -d1) debugging switch causes sendmail to print its interpretation of whom the message is from (the name of the sender as it was used in the envelope):

From person = "sender"

Here, sender is the user portion of the mail address of the sender. This output is most useful when combined with the -f command-line switch (which sets the name of the sender from the command line; see Section 36.7.21, -f and -r).

37.5.11 -d1.5

Dump the sender address

The -d1.5 debugging switch causes additional information about the sender to be printed. That output looks like this:

main: QDONTSEND output of printaddr() here (see Section 37.3.1, "The Output Produced by printaddr()")

The QDONTSEND means that the sender is not a recipient and so should not get a copy of the message. That is followed by the output of the printaddr() routine.

37.5.12 -d2.1

End with finis()

Ordinarily, sendmail exits silently when it is done (unless an error causes an error message to be printed). The -d2.1 (a.k.a. -d2) debugging switch causes sendmail to print three useful values when it exits. The message it prints looks like this:

====finis: stat num e_id=qid e_flags=flags

The num is the final value of the sendmail program's global ExitStat variable. It is usually updated to contain the latest error value as defined in <sysexits.h>. See Section 36.5, "sendmail's exit() Status" for a detailed description of the possible exit values.

The qid is either the queue identifier (such as SAA24069) or the NOQUEUE if the message was never assigned an identifier (such as if it was never queued).

The flags is a hexadecimal representation of the possible envelope flags followed by a text representation of those flags in angle brackets with the leading EF_ removed, for example,

201003<OLDSTYLE,INQUEUE,GLOBALERRS,HAS_DF>

These are the envelope flags that were in effect with the current envelope when sendmail exited. The possible values are shown in Table 37.3.

Table 37.3: Hexadecimal Envelope Flags
TextHexDescription
EF_OLDSTYLE0000001Use spaces (not commas) in headers
EF_INQUEUE0000002This message is fully queued
EF_NO_BODY_RETN0000004Omit message body on error
EF_CLRQUEUE0000008Disk copy is no longer needed
EF_SENDRECEIPT0000010Send a return receipt
EF_FATALERRS0000020Fatal errors occurred
EF_KEEPQUEUE0000040Keep queue files always
EF_RESPONSE0000080This is an error or return receipt
EF_RESENT0000100This message is being forwarded
EF_VRFYONLY0000200Verify only (don't expand aliases)
EF_WARNING0000400Warning message has been sent
EF_QUEUERUN0000800This envelope is from queue
EF_GLOBALERRS0001000Treat errors as global
EF_PM_NOTIFY0002000Send return mail to postmaster
EF_METOO0004000Send to me too
EF_LOGSENDER0008000Need to log the sender
EF_NORECEIPT0010000Suppress all return-receipts
EF_HAS8BIT0020000At least one 8-bit character in body
EF_NL_NOT_EOL0040000Don't accept raw newline as end-of-line
EF_CRLF_NOT_EOL0080000Don't accept carriage-return/line-feed as end-of-line
EF_RET_PARAM0100000SMTP RCPT command had RET argument
EF_HAS_DF0200000Set when df file is instantiated
EF_IS_MIME0400000Really is a MIME message
EF_DONT_MIME0800000This message is not MIME-able

For example, if the message were fully queued and required a DSN return receipt, the flags would print as

e_flags=12<INQUEUE,SENDRECEIPT>

Note that this line of output is also produced by the -d13.1, -d40.3, and -d50.1 debugging switches but under different circumstances.

37.5.13 -d2.9

Show file descriptors with dumpfd()

The -d2.9 debugging switch tells sendmail to display the properties of each open file descriptor. That output is produced by the dumpfd() routine, and each line of output is for a single file descriptor:

num: fl=flags mode=mode type stats

Here, the num is the number of the open file descriptor. Note that descriptors 0, 1, and 2 are usually tied to the standard input, output, and error output.

The flags is a hexadecimal representation of the state flags associated with a file descriptor. F_GETFL is used with ioctl(2) to fetch each, and all are described in <sys/fcntlcom.h>.

The mode is printed in octal and is the st_mode associated with an fstat(2) of the file descriptor. The type examines the file type portion of the st_mode and prints SOCK for a socket, CHR: for a character special device, BLK: for a block special device, FIFO: for a first-in-first-out file, DIR: for a directory, LNK: for a symbolic link, and nothing otherwise (e.g., nothing if it is a file).

The stats are printed for all but the socket. They look like this:

dev=major/minor ino=inum nlink=nlink u/gid=uid/gid size=bytes

Here the dev= shows the major and minor device numbers for the device that the file descriptor is associated with. The inum is the inode number on the disk (if there is one) and nlink is the number of hard links to the file on disk. The uid/gid shows the user and group ownership associated with the file descriptor. The size is the number of bytes in a file, and 0 for almost everything else.

For a socket, the stats part of each line looks like this:

[addr]/port-> host

Here, addr is the IP address of the local end of the socket. If the connection is of type AF_INET, the port number of the connection is also shown as /port. The host is the hostname, as returned by getpeername(3), of the connecting host. If any of these cannot be found, the error string associated with errno is printed parenthetically in its place.

The -d7.9, -d40.9, and -d46.9 debugging switches also print a line like this for specific file descriptors. Also if sendmail is run with the -d10.100 switch, or if sendmail fails to open a tf queue file (see Section 23.2.6, "The Temporary qf Rewrite Image: tf"), or if sendmail exited because of too many open files, it will syslog all its open file descriptors within this format.

37.5.14 -d3.1

Print load average

The sendmail program queues mail, rather than delivering it, if the load average (number of processes in the run queue) exceeds the value set by the QueueLA (x) option (see Section 34.8.50, QueueLA (x)). Exceeding that value also prevents messages that are already in the queue from being delivered (prevents a queue run). If the load average becomes higher than the value of the RefuseLA (X) option (see Section 34.8.54, RefuseLA (X)), sendmail rejects incoming SMTP connections until the load average drops.

The -d3.1 debugging switch (a.k.a. -d3) causes sendmail to print the load average found by its internal getla() routine each time that routine is called:

getla: la

Here, la is the current load average printed as an integer. If sendmail was compiled with LA_TYPE==LA_ZERO (see Section 18.8.14, LA-TYPE), the following will be printed to show that your sendmail binary completely lacks load averaging support:

getla: ZERO

The -d3.1 debugging switch also causes sendmail to print any errors it encounters while obtaining the load average.

getla: open(/dev/kmem): error

Here, /dev/kmem is the device that is used to access kernel memory. The error is the system error that caused the failure, such as "Permission denied" if sendmail is not properly sgid to the group kmem.

getla: nlist(unix): error

The nlist(3) function extracts a list of symbols from an executable binary (among them the symbol for the load average). The binary that it extracts is the kernel whose pathname is unix (such as /vmunix for SunOS 4.x). Here, the error is the reason nlist(3) failed. One possibility is that you booted from a nonstandard kernel name (such as /vmunix.new) and the expected file didn't exist:

getla: nlist(unix, la) ==> 0

If the expected kernel exists (unix) but the machine was booted from a different kernel, the symbol representing the load average may not be found. In that instance, la is the name of the kernel variable that sendmail was trying to find.

37.5.15 -d3.5

Print load average

The load average that sendmail uses is averaged over the last minute. Internally, the kernel keeps track of three load averages. In addition to the last minute, it also tracks the last 5 and 15 minutes. The -d3.5 debugging switch causes V8 sendmail to print the load average over the last minute:

getla: averun = 1min

37.5.16 -d3.15

Print three load averages

The -d3.15 debugging switch causes V8 sendmail to print all three load averages:

getla: averun = 1min, 5min, 15min

Here, the three load averages are printed either in integer or in floating point, depending on the setting of LA_TYPE (see Section 18.8.14).

37.5.17 -d3.20

Show offset for load average

The nlist(3) routine (described above) provides the offset into the kernel file where the value of the load average is found. The -d3.20 debugging switch causes that offset to be displayed:

getla: symbol address = offset

Here, the offset is printed in hexadecimal. The load average is read by seeking in the kernel file and reading it. If the seek or read fails, the -d3.1 debugging switch causes sendmail to print:

getla: seek or read: error

This can indicate a wrong or corrupted kernel image.

37.5.18 -d3.30

Show result of decision to queue

The internal routine shouldqueue() is called just before a mail message is delivered to recipients. That routine determines whether mail will be delivered or queued on the basis of the current load average and message priority. Upon entry it prints:

shouldqueue: CurrentLA=load, pri=priority

If the CurrentLA is less than the limit set by the QueueLA (x) option (see Section 34.8.50), sendmail prints:

FALSE (CurrentLA < QueueLA)

Then the calculation described in Section 34.8.49, QueueFactor (q) for the QueueFactor (q) option is performed using the pri priority. The result is printed as one of the following, where TRUE represents a zero result and FALSE represents a nonzero result:

TRUE (by calculation)
FALSE (by calculation)

37.5.19 -d4.80

Trace enoughspace()

(useful)

The MinFreeBlocks (b) option (see Section 34.8.40, MinFreeBlocks (b)) defines the minimum number of disk blocks that must be reserved on the queue disk. If an incoming SMTP message will fill the disk beyond this minimum, the message is rejected.

The -d4.80 debugging switch [1] traces the enoughspace() routine in conf.c. That routine examines the disk space and allows or disallows incoming mail.

[1] No -d4.1 (a.k.a. -d4) information is available.

enoughspace: no threshold

This debugging output says that no limit was defined with the MinFreeBlocks (b) option.

enoughspace: bavail=haveblocks need=needblocks

This debugging output shows that the number of blocks free (available) on the disk is haveblocks and that the number of blocks required by incoming mail is needblocks. Note that haveblocks will always be -1 if sendmail was compiled with SFS_TYPE set to SFS_NONE (see Section 18.8.40, SFS-TYPE).

enoughspace failure: min=boption need=needblocks

If the required number of blocks (needblocks) exceeds the minimum reserved as defined by the MinFreeBlocks (b) option (boption), use of the disk is disallowed.

37.5.20 -d5.4

Tick for queued events

Throughout its many possible levels of forks and children, sendmail must keep track of timeouts - the maximum amount of time it should wait for an event to occur. For example, a child must not wait forever for an SMTP greeting message, because the program at the other end may never provide that message (because it died or is just too busy).

To keep track of which child should be notified at which time, sendmail maintains an internal queue of events. The sendmail program uses the SIGALARM signal and the alarm(2) system call to set the interval it waits to next check its queue of events for timeouts. That interval (called a tick) is the period of the timeout itself, or if the timeout is scheduled for the present or past, the interval is three seconds. The -d5.4 debugging switch [2] causes sendmail to print the current time whenever the queue of events is examined:

[2] There is no -d5.1 (a.k.a. -d5) information.

tick: now=time

Here, time is the current time in seconds as returned by time(2).

37.5.21 -d5.5

Events set and cleared

Events are set by the process (child or parent) that needs a timeout. The -d5.5 debugging switch causes sendmail to print the information that is used to set up for that timeout:

setevent: intvl=secs, for=timeo, func=addr, arg=pass, ev=evnt

The information is the timeout interval in seconds (secs), the time (now plus the interval) in seconds that the timeout will occur (timeo), the address in memory of the subroutine that will be called if a timeout occurs (addr), the argument to be passed to that subroutine (pass), and the address in memory of the C language structure that contains this information (evnt). The addr of the function to be called can be converted to a function name by running nm(1) on an unstripped binary of sendmail. For example, if the following output was produced by /usr/lib/sendmail:

setevent: intvl=3600, for=802463800, func=3ebc4, arg=0, ev=94b68

you could find the function name associated with the address 3ebc4 by running

%  nm /usr/lib/sendmail | grep 3ebc4
0003ebc4 t _readtimeout

Here, the result is the name readtimeout, which corresponds to the function readtimeout() in util.c.

When an event is cleared because a timeout was no longer needed, sendmail prints:

clrevent: ev=evnt

Here, evnt is the address in memory of the C language structure that stored the event information. This is the same as the last item printed by setevent above.

37.5.22 -d5.6

Show events triggered

The -d5.6 debugging switch tells sendmail to print the following information when a timeout occurs:

tick: ev=evnt, func=addr, arg=pass, pid=pid

This shows that the event stored in the C language structure, whose address in memory is evnt, has timed out. The subroutine whose address in memory is addr will be called with an argument of pass. The process identification number of the parent process that asked for the timeout is shown as pid.

37.5.23 -d6.1

Show failed mail

(useful)

Mail can fail for a wide variety of reasons. The way that sendmail handles errors is determined by the setting of the ErrorMode (e) option (see Section 34.8.24, ErrorMode (e)) in the configuration file. The -d6.1 (a.k.a. -d6) debugging switch causes sendmail to print the error-handling mode that is in effect at the time it first begins to handle failed mail:

savemail, errorMode = char, id = qid, ExitStat = err
e_from= <- output of printaddr() here (see Section 37.3.1)

Here, char is either: p for print errors; m for mail back errors; w for write back errors; e for special BERKnet processing; or q for "don't print anything" (all of which are described under the ErrorMode option in Section 34.8.24). The qid is the queue identifier (such as KAA15019). The err is the error that caused the message to fail (as defined in <sysexits.h>). And e_from= uses printaddr() to print details about the sender's address.

If the error-processing mode is m (for mail back) and the -d6.1 debugging switch is in effect, sendmail prints details about how the message is being returned to the sender:

***Return To Sender: msg=reason, depth=num, e=addr, returnq=
<- output of printaddr() here (see Section 37.3.1)

Here, reason is a quoted string of text that explains why the mail failed. This may be an SMTP reply string. The num is zero for normal delivery and one for error delivery. The addr is the location in memory of the information about the current envelope. Finally, sendmail calls printaddr() to print the details of the queue of recipients (returnq=) for the current message.

37.5.24 -d6.5

The current error state

The -d6.5 debugging switch tells sendmail to print the error state it was in when it finished processing the error that caused the message to fail:

state num

If num is 7 (successful delivery), nothing is printed. Otherwise, the above message is printed, and the value of num represents one of the states shown in Table 37.4.

Table 37.4: Error Handling States
StateDescription
0Report to sender's terminal
1Mail back to sender
2Messages have already been returned
3Save in ~/dead.letter
4Return to postmaster
5Save in /usr/tmp/dead.letter
6Leave the locked queue/transcript files
7The message has been successfully delivered

37.5.25 -d6.20

Show sender of return to sender

The -d6.20 debugging switch tells sendmail to print additional information to that printed by -d6.1. Specifically, it prints, via printaddr(), the address information about the sender of returned mail:

***Return To Sender: msg=reason, depth=num, e=addr, returnq=
output of printaddr() here (see Section 37.3.1)
Sendq= output of printaddr() here

37.5.26 -d7.1

The Queue filename

The sendmail program stores mail messages in its queue for a variety of reasons. For example, the SuperSafe (s) option (see Section 34.8.67, SuperSafe (s)) causes it to queue all messages just to be safe. Also, messages that cannot be delivered because of a temporary lack of resources (or for any correctable reason) are queued for later delivery.

Mail messages are stored in the queue in two parts. A data part contains the body of the message. An information part stores headers and other information about the message. The filenames of the two parts are identical but for the first two letters. A df begins the name of the data part, and a qf begins the name of the information part. A third type of queue file begins with the letters xf and is a "transcript" file that holds error messages produced during delivery.

To ensure that these filenames do not conflict with the names of files that may already be in the queue, sendmail uses the following pattern to create new names:

qfHAApid

Here, pid is the process identification number of the incarnation of sendmail that is trying to create the file. Because sendmail often fork(2)'s to process the queue, the pid is likely unique and therefore creates a unique name.

The H represents the current hour of the day (using a 24-hour clock) and prefixes the AA. It is constructed by adding the current hour to the letter A (thus 00:23 would produce A+0=A, while 15:45 would produce A+15=P). Although it is not recommended, the hour character can be useful in viewing the queue (with the -bp command-line switch) to observe the particular hours, if any, that messages tend to queue. The hour prefix does not increment.

If sendmail cannot create a file (because a file with that name already exists), it increments the rightmost A of the AA part of the name to a B and tries again. It continues this process, incrementing the right from A to Z and the left from A to ~ until it succeeds. If a unique name cannot be found, sendmail has failed in its attempt to queue the message. The last filename tried is:

qfH~Zpid

This name is unlikely to ever appear, because the clocking provides for over 1600 possible unique names. With some versions of sendmail, however, it may appear if the queue directory is not writable. For example, the -C command-line switch, when used by a normal user, might cause sendmail to give up its root privilege, thus causing this message to be printed.

The -d7.1 (a.k.a. -d7) debugging switch causes sendmail to print the portion of the queue name that is common to all the files that constitute a single queued message.

queuename: assigned id HAApid, env=addr

Here, sendmail prints the identifier portion of the filename (the HAA, or whatever letters succeeded, and the pid) that is common to the df, qf, and xf files. The addr is the address in memory of the C language structure that describes the envelope for the mail message that is queued.

37.5.27 -d7.2

Show assigned queue file name

The -d7.2 debugging switch tells sendmail to print the full filename of the file that it just created in the queue directory:

queuename: letterfHAApid

The first letter of the name is either d, q, or x. The pid is the process identification number of the sendmail process that created the file.

37.5.28 -d7.9

Dump file descriptor for the qf file

Once sendmail successfully opens its qf file, it has established the unique identifier. The -d7.9 debugging switch causes sendmail to dump the file-descriptor for that open file:

lockfd= output of dumpfd() here (see Section 37.5.13)

37.5.29 -d7.20

Show queue names being tried

The -d7.20 debugging switch causes sendmail to print each filename that it is attempting to try as it clocks the AA in the name from AA to ~Z:

queuename: trying qfHAA16391
queuename: trying qfHAB16391
queuename: trying qfHAC16391
queuename: trying qfHAD16391
... <- and so on

37.5.30 -d8.1

DNS name resolution

(useful)

Name resolution is the process of determining a machine's IP address based on its fully qualified domain name. This is done by using the Domain Name System (DNS). The process that sendmail uses to resolve a name is described in Section 21.2, "How sendmail Uses DNS".

When sendmail finds that a hostname is really an MX (mail exchanger) record, it attempts to look up the A record for the host that handles mail receipt. That request may fail for a variety of reasons. If the -d8.1 (a.k.a. -d8) debugging switch is specified, sendmail produces the following message:

getmxrr: res_search(host) failed (errno=err, h_errno=herr)

Here, host is the hostname that was being looked up, err is the system error number (if any) from <errno.h>, and herr is the resolver specific error from <netdb.h> as shown in Table 37.5.

Table 37.5: Resolver Errors from netdb.h
ValueMnemonicDescription
1HOST_NOT_FOUNDHost not found (authoritative answer returned)
2TRY_AGAINNonauthoritative server not found or server failure
3NO_RECOVERYNonrecoverable errors and refusals
4NO_DATAValid name but no record of requested type

37.5.31 -d8.2

Call to getcanonname(3)

(useful)

The routine dns_getcanonname() in domain.c of the sendmail source converts a hostname to a fully qualified domain name. This routine is called only if DNS is used to look up hostnames, as determined by the ResolverOptions (I) option (see Section 34.8.55, ResolverOptions (I)) and the ServiceSwitchFile option (see Section 34.8.61). If it is, dns_getcanonname() can be called from two places: during startup to get the values for $w, $j, and $m (see Section 37.5.2) or when a host is looked up via the $[ and $] canonify-operators (see Section 28.6.6, "Canonicalize Hostname: $[ and $]").

The -d8.2 debugging switch shows the hostname before it is fully qualified with this call:

dns_getcanonname(host, flag)

If the flag is nonzero, calls to the getmxrr() routine (which looks up MX records) are also traced. On entry to that routine, sendmail will print:

getmxrr(host, droplocalhost=bool)

The host is the hostname that MX records are being looked up for. The bool, if nonzero, means that all MX records that are less preferred than the local host (as determined by $=w) will be discarded. If zero, they will be retained.

The -d8.2 debugging switch also causes sendmail to show the result of processing the ResolverOptions (I) option's settings (see Section 34.8.55) while reading the configuration file:

_res.options = hex, HasWildcardMX = 1 or 0

The hex is a hexadecimal representation of the state structure's options variable as described in <resolv.h>. The value of HasWildcardMX is determined by its prefix (+ or -) when listed with the ResolverOptions (I) option.

37.5.32 -d8.3

Trace dropped local hostnames

(useful)

If a hostname is dropped because bool (above) is nonzero, the -d8.3 switch causes sendmail to print the following:

found localhost (host) in MX list, pref=pref

The host is the hostname that is being dropped. The pref is the preference associated with the MX record.

37.5.33 -d8.5

Hostname being tried in getcanonname(3)

(useful)

The -d8.5 debugging switch causes the getcanonname(3) routine to print the hostname it is trying to fully qualify. It shows the name with the local domain appended without the local domain appended, and at each step in between. Each try is printed as:

getcanonname: trying host.domain (type)

Here, the type is the type of lookup and is either ANY, A, or MX.

37.5.34 -d8.7

Yes/no response to -d8.5

(useful)

The -d8.7 debugging switch causes sendmail to print a yes or no response to each of the "trying" lines printed by -8.5. Yes means that the host could successfully be fully canonicalized. A yes answer prints just this:

YES

If the host could not be canonicalized, a more complex answer is printed:

NO: errno=err, h_errno=herr

The err is the system error number (if any) from <errno.h>, and herr is the resolver specific error from <netdb.h> as shown in Table 37.5.

37.5.35 -d8.8

Resolver debugging

(useful)

The -d8.8 debugging switch causes the resolver library to be put into debugging mode (if that was mode was included when that library was compiled). The ResolverOptions (I) option (see Section 34.8.55) +DEBUG also turns on this debugging mode. But be aware that turning on +DEBUG will cause a large number of screens full of output to be produced by the resolver library for every DNS lookup.

If the name server returns an answer to an MX lookup, and if the answer is not an MX record or an error, sendmail will skip that host. The -d8.8 debugging switch (or the resolver library being in debug mode) then causes sendmail to print the following:

unexpected answer type wrongtype, size bytes

The wrongtype is an integer that can be found in <arpa/nameser.h>.

37.5.36 -d8.20

Inconsistency in returned information

Internally, the resolver library (libresolv.a) stores host domain names in compressed form (for transmission efficiency). We won't cover the nature of that compression. For our purposes it is sufficient to know that the sendmail program calls dn_skipname(3) from the resolver library to skip past the compressed part of a host domain name. That call should never fail, but if it does, the -d8.20 debugging switch causes sendmail to print:

qdcount failure (questions)

The questions is a count of the number of queries made.

37.5.37 -d9.1

Canonify hostname and RFC1413 queries

The -d9.1 (a.k.a. -d9) debugging switch can be used to watch sendmail convert hostnames and addresses into canonical form. This is done by watching the host_map_lookup() function with -d9.1. First the hostname is looked up in the symbol table. If it exists there and if it is marked as a valid canonical entry, sendmail prints

host_map_lookup(host) => CACHE canon

Here, the name host was found in the symbol table. The value returned was a valid canonical name. If host had not been found, the canon would have printed as NULL.

If sendmail is running in defer-delivery mode (see the DeliveryMode (d) option in Section 34.8.16, DeliveryMode (d)), it will skip looking up the hostname further. This is done because dial-on-demand connections should not be brought up merely to perform unnecessary DNS lookups. When sendmail skips further lookups, it prints:

host_map_lookup(host) => DEFERRED

If the name is not in the symbol table, it is looked up with the getcanonname() function. First sendmail prints:

host_map_lookup(host) =>

with no trailing newline. Then, if the canonical name is returned by getcanonname(), that returned name is printed. Otherwise, FAIL is printed. If sendmail is compiled with NAMED_BIND defined for DNS support (see Section 18.8.23, NAMED-BIND), the FAIL is followed by the resolver specific error (herr) from <netdb.h>:

host_map_lookup(host) => herr

The -d9 debugging switch is also used to display identd(8) queries. When a network connection is made from a remote host to the local host, the local sendmail uses the RFC1413 identification protocol to query the remote host for the name of the user who instantiated the connection. The result of that query is printed as:

getauthinfo: result

Here, result is two pieces of information: an address composed of the username, an @, and the real name of the remote host and the IP address of that host:

getauthinfo: george@fbi.dc.gov [123.45.67.8]

If the query fails, nothing is printed.

37.5.38 -d9.3

Show raw RFC1413 reply

The above information is not provided by the remote host in that clear form. Instead, sendmail needs to parse the needed information from a raw reply. The -d9.3 debugging switch causes the raw reply to be printed:

getauthinfo:  got raw_reply

37.5.39 -d9.10

Show RFC1413 query being sent

The -d9.10 debugging switch causes sendmail to display its outgoing RFC1413 query:

getauthinfo: sent query

Here, the outgoing query is composed of two numbers: the TCP port on the remote machine where its RFC1413 server is running, followed by a dot and the local port number for the original connection.

37.5.40 -d10.1

Show recipient delivery

When sendmail is about to deliver a mail message, it has already resolved three pieces of information: which delivery agent to use, the name of the host that receives the message, and the name of one or more recipients for that message. The -d10.1 (a.k.a. -d10) debugging switch tells sendmail to display information about the recipient to whom it is about to deliver:

-deliver, id=mid, mailer=num, host=`hname', first user=`uname'

Here, mid is the queue message identifier (such as PAA08463). The num is the number of the delivery agent selected. Delivery agent numbers can be displayed by using the -d0.15 debugging switch. The hname is the name of the host that receives delivery. The uname is the name of the first of possibly many users who receive the mail message. The uname can be either a single name such as joe or a full forwarding address such as joe@jokes.are.us.

When sendmail attempts delivery, it may be delivering to multiple recipients. It stores its list of recipients internally as a linked list of C language structures, each of which holds information that is specific to each recipient address. The -d10.1 debugging switch also causes sendmail to print that information using the printaddr() routine:

send to output of printaddr() here (see Section 37.3.1)

37.5.41 -d10.2

Dump controlling user's address

Every recipient address may have a controlling user associated with it (see Section 23.9.2, C line). The -d10.2 causes sendmail to dump the address of the controlling user using the printaddr() routine:

ctladdr= output of printaddr() here (see Section 37.3.1)

37.5.42 -d10.5

Showq don't send to MeToo address

If the MeToo (m) option (see Section 34.8.39, MeToo (m)) is set to false, the -d10.5 debugging switch tells sendmail to dump the address that won't receive (the QDONTSEND) the mail message.

deliver: QDONTSEND output of printaddr() here (see Section 37.3.1)

37.5.43 -d10.100

Predelivery file descriptor dump

The -d10.100 debugging switch tells sendmail to dump all its file descriptors just before it is about to attempt delivery.

37.5.44 -d11.1

Trace delivery

(useful)

The -d11.1 (a.k.a. -d11) debugging switch is used to trace message delivery. For each delivery agent the following is printed:

openmailer: argv

Here, argv is the A= array for the delivery agent, with macros expanded and printed.

The status of remote hosts is cached internally. Before connecting to a remote host, sendmail checks its cache to see whether that host is down. If it is, it skips connecting to that host. If the -d11.1 debugging switch is also specified, the status of the down host is printed as:

openmailer: output of mci_dump() here

The output of mci_dump() looks like this:

MCI@memaddr: flags=mci_flags<flag,flag,...>, 
errno=mci_errno, herrno=mci_herrno, exitstat=mci_exitstat, state=mci_state,
pid=mci_pid, maxsize=mci_maxsize, phase=mci_phase, mailer=mci_mailer,
host=mci_host, lastuse=mci_lastuse

The meaning of each mci_ item in the above output is described in Table 37.6.

Table 37.6: The Meaning of the MCI Structure Items
NameWhat prints
mci_memaddrThe address in memory of this C language structure
mci_flagsThe flag bits in hexadecimal (see Table 37.7)
mci_errnoThe error number of the last connection
mci_herrnoThe DNS h_errno of the last lookup
mci_exitstatThe <sysexits.h> exit status of last connection
mci_stateThe current SMTP state (see Table 37.16)
mci_maxsizeThe maximum size message the host will accept
mci_pidThe PID of the child process
mci_phaseSMTP phase (string) such as "client greeting" (or NULL)
mci_mailerThe (text) name of the delivery agent (or NULL)
mci_hostThe host's name (or NULL)
mci_lastuseLast usage time in ctime(3) format

Table 37.7 shows what the individual flag bits in mci_flags mean, and the human-readable flags text that corresponds to each bit. Those text items are shown with the leading source MCIF_ prefix removed.

Table 37.7: The Meaning of mci_flags Hexadecimal Values
ValueNameMeaning
0001VALIDThis entry is valid
0002TEMPDon't cache this connection
0004CACHEDThis connection currently in open cache
0008ESMTPThis host speaks ESMTP
0010EXPNEXPN command supported
0020SIZESIZE option supported
00408BITMIMEBODY=8BITMIME supported
00807BITStrip this message to 7 bits
0100MULTSTATMAIL11V3: handles MULT status
0200INHEADERCurrently outputting header
0400CVT8TO7Convert from 8 to 7 bits
0800DSNDSN extension supported
10008BITOKOK to send 8-bit characters
2000CVT7TO8Convert from 7 to 8 bits
4000INMIMECurrently reading MIME header

After checking to see whether the host is down, sendmail attempts to connect to it for network SMTP mail. If that connect fails, the -d11.1 debugging switch causes the following to be printed:

openmailer: makeconnection => stat=exitstatus, errno=errno

Here, exitstatus is a numerical representation of the reason for the failure as documented in <sysexits.h>, and errno is the system-level reason for the error, as documented in <errno.h>.

Other errors, such as failure to establish a pipe(2), or failure to fork(2), causes the following to be printed:

openmailer: NULL

This message (although it contains no information) signals that a more descriptive error message was logged with syslog(3) (see Section 26.1, "Logging with syslog").

37.5.45 -d11.2

Show the uid/gid running as during delivery

(useful)

To perform delivery, sendmail often has to set its uid to something other than root's. The logic behind that process is described in Section 24.2.2. The -d11.2 debugging switch tells sendmail to print the real and effective uid's that it is running under during delivery.

openmailer: running as r/euid=ruid/euid

Also, the -d11.2 debugging switch causes sendmail to print any error response that may be produced by a delivery agent:

giveresponse: stat=status, e->e_message=what

Here, status is the error that caused delivery to fail (or succeed if it is 0) as defined in <sysexits.h>. The what is either the error message produced by the delivery agent or "<NULL>" if the delivery agent was silent.

37.5.46 -d11.20

Show tried D= directories

Execution of a delivery agent can take place in any of a sequence of directories as defined by the D= delivery agent equate (see Section 30.4.3, D=). The -d11.20 debugging switch causes each directory to be printed as it is tried:

openmailer: trydir dir

Here, dir is the name of the directory that sendmail is about to chdir(2) into.

37.5.47 -d12.1

Show mapping of relative host

(useful)

In the SMTP RCPT command, sendmail is required to express the recipient's address relative to the local host. For domain addresses, this simply means that the address should be RFC822-compliant.

The -d12.1 (a.k.a. -d12) debugging switch causes sendmail to print the address as it appeared before it was made relative:

remotename(addr)

If the addr is for the sender or recipient and is being processed from a queue file, then nothing more is printed, and the addr is processed by rule set 3. If the delivery agent for the recipient has the F=C flag set (see Section 30.8.15, F=C) and the recipient address lacks a domain part, then the domain of the sender is appended, and the result is processed by rule set 3 again. Sender/recipient-specific rule sets are then applied (1 and S= for the sender, or 2 and R= for the recipient). Next, rule set 4 is applied, and any macros in the result are expanded. Finally, the fully qualified and relative address is printed as:

remotename => `addr'

37.5.48 -d13.1

Show delivery

(useful)

The -d13 (a.k.a. -d13) debugging switch causes sendmail to display information about the recipients of each mail message as it is being delivered. The -d13.1 debugging switch tells sendmail to print the mode of delivery and then the recipient information:

SENDALL: mode dmode, id=mid, e_from output of printaddr() here (see Section 37.3.1)
        e_flags = envelope flags here
        sendqueue:
output of printaddr() here (see Section 37.3.1)

Here, dmode is one of those shown in Table 37.8. The mid is the queue message identifier (such as PAA08463). The address of the sender, e_from, is dumped by using the printaddr() routine. Then the envelope flags, e_flags, are dumped as described in Table 37.3. Next, information about all the recipients (sendqueue:) is printed by using the printaddr() routine.

Table 37.8: Delivery Modes Used by sendall()
ModeDescription
iInteractive delivery
jDeliver w/o queueing (obsolete as of V8)
bDeliver in background
qQueue, don't deliver
dDefer, queue w/o DNS lookups
vVerify only (used internally)

Finally, the -d13.1 debugging switch causes sendmail to print a message every time it splits an envelope in two:

sendall: split orig into new

Here, orig is the original queue message identifier for the original envelope (such as PAA08463) and new is the identifier for the new envelope, the near identical clone of the first. Envelopes need to split if they have different owners.

37.5.49 -d13.5

Show addresses that we should not send to

The -d13.5 debugging switch is used to display addresses to which mail should not be delivered. One such address is that of the sender of the cloned envelope after a split:

sendall(split): QDONTSEND output of printaddr() here (see Section 37.3.1)

Another is the sender address (unless the MeToo (m) option, see Section 34.8.39, is set):

sendall: QDONTSEND <-output of printaddr() here (see Section 37.3.1)

Finally, senders who are the owner- of mailing lists (see Section 25.3, "Defining a Mailing List Owner") should not have mail sent to them.

sendall(owner): QDONTSEND <-output of printaddr() here (see Section 37.3.1)

This latter sender address is derived by a call to setsender(), which can be separately viewed with the -d45 debugging switch.

37.5.50 -d13.10

Trace sendenvelope()

The -d13.10 debugging switch causes sendmail to print the following upon entering its internal sendenvelope() routine:

sendenvelope(ident) e_flags=hex

The ident is either the queue identifier (such as SAA24069) or the [NOQUEUE] if the message was never assigned an identifier (such as if it was never queued). The e_flags are dumped in hexadecimal as described in Table 37.3.

37.5.51 -d13.20

Show final mode

The sendmail program's delivery mode (as initially set with the DeliveryMode (d) option; see Section 34.8.16) can change during delivery for a complex series of reasons. The -d13.20 debugging switch causes the final delivery mode to be displayed:

sendall: final mode = char

Here, char is the one of the characters that can be specified for the DeliveryMode (d) option.

37.5.52 -d13.29

Show auto-queueing

If, after all recipient addresses are checked, none are left to be delivered to (everyone of them was either dropped or queued), and if the DeliveryMode (d) option (see Section 34.8.16) is neither q, d, nor v, the -d13.29 debugging switch will cause sendmail to print:

No deliveries: auto-queuing

37.5.53 -d13.30

Show envelopes being split

The process of creating another envelope for another sender is called "splitting the envelope." The -d13.30 debugging switch causes sendmail to show its initial scanning of the send queue to count the number of envelopes (including split envelopes) that will be needed.

Checking output of printaddr() here (see Section 37.3.1)

Then, depending on the result, each owner will have one of the following printed:

... QDONTSEND
    ... QBADADDR|QQUEUEUP
    ... expensive
    ... deliverable

The Q flags are described under the output of printaddr() in Section 37.3.1.

37.5.54 -d14.2

Show header field commas

Some programs require that addresses in a list of recipients be separated from each other by space characters. This is called an "old-style" address. RFC822 requires that addressees be separated from each other with comma characters.

The -d14.2 [3] debugging switch tells sendmail to show each header line that may need spaces converted to commas.

[3] There is no -d14.1 information.

commaize(header: list)

Here, header is the caption part of a header line, such as From:. The list is a sequence of one or more addresses.

37.5.55 -d15.1

Show network get request activity

When sendmail runs in daemon mode, it opens a socket on a port, then listens on that socket for incoming SMTP connections. The -d15.1 (a.k.a. -d15) debugging switch prints information about both of those steps. Note that -d15.1 should usually be combined with -d99.100, or some output may be lost.

Before the socket is opened, sendmail prints the following:

getrequests: port 0xportno

This shows that the port numbered portno (printed in hexadecimal notation) is used to open the socket. If that open fails, sendmail syslog(3)'s one of the following messages at LOG_CRIT and exits:

getrequests: problem creating SMTP socket

If the open succeeds, sendmail attempts to bind to that socket. If it cannot bind, it syslogs the following message at LOG_CRIT and exits:

getrequests: can't bind socket

After it binds, sendmail goes into a loop in which it listens for and handles incoming SMTP requests. If the listen fails, sendmail syslog(3)'s the following message at LOG_CRIT and exits:

getrequests: cannot listen

If sendmail starts to listen successfully, this -d15.1 debugging switch causes it to print the number of the socket on which it is listening:

getrequests: sockno

This shows that sendmail is then listening on the socket whose file descriptor is sockno.

37.5.56 -d15.2

Incoming connections

In daemon mode, sendmail waits for an incoming SMTP connection. When that connection is made, sendmail forks, and the child processes the connection from that point on. The -d15.2 debugging switch causes sendmail to print a message that confirms that it is performing this fork. Note that -d15.2 should usually be combined with -d99.100, or some output may be lost:

getrequests: forking (fd = sock)

Here, sock is the value of the socket being used for the connection. The -d15.2 debugging switch also causes a message to be printed when the child process exits:

getreq: returning (normal server)
getreq: returning (null server)

Here, failure of the connection to be validated (see Section 22.4.1, "Accept/Reject Connections via libwrap.a" and Section 29.10.3, "The check_relay Rule Set"), causes null server to be printed. A successful connection causes normal server to be printed.

Finally, the -d15.2 debugging switch causes the following to be printed every time opendaemonsocket() routine is called:

opendaemonsocket()

37.5.57 -d15.101

Kernel TCP debugging

On kernels that support this feature, the -d15.101 debugging switch turns on kernel debugging for the socket that is opened to handle an incoming SMTP connection. Debugging is turned off when the socket is closed at the end of receipt of the message. The debugging information gathered can be viewed with the trpt(8) program.

37.5.58 -d16.1

Outgoing connections

When mail messages are sent to a site that can be reached via a TCP/IP connection, the -d16.1 (a.k.a. -d16) debugging switch causes sendmail to print one of the following messages when it is about to make the connection:

makeconnection: (host [NULLADDR])            <- null address
makeconnection: (host [0])                   <- no address family
makeconnection: (host [[UNIX: path]])        <- AF_UNIX family
makeconnection: (host [ip address])          <- AF_INET family
makeconnection: (host [[LINK: name]])        <- AF_LINK family
makeconnection: (host [Family num:0xbytes])  <- unknown family

Here, host is the name of the host to which the connection is made. The form of the address information differs depending on the address family. If the connection can be successfully made, the -d16.1 debugging switch then causes sendmail to print:

makeconnection: fd=sock

Here, sock is the socket descriptor that was issued for use with the socket connection.

If the DialDelay option (see Section 34.8.17, DialDelay) is nonzero and the connection fails, sendmail will sleep DialDelay seconds and try again. If the -d16.1 debugging switch is also specified, sendmail will print:

Connect failed (error message); trying again...

Here, error message describes the reason for the initial failure.

If there is more than one address for a host, sendmail will try each in turn until one connects successfully. The -d16.1 debugging switch causes the following to be printed for each failure:

Connect failed (error message); trying new address....

Note that the -d16 debugging switch should usually be combined with the -d99.100 debugging switch, or some output may be lost.

37.5.59 -d16.101

Kernel TCP debugging

See -d15.101. The only difference here is that debugging is turned on for the outgoing socket.

37.5.60 -d17.1

List MX hosts

When sendmail readies to deliver mail to a remote host, it looks up that host using DNS to find Mail Exchanger (MX) records. The -d17.1 (a.k.a. -d17) debugging switch causes V8 sendmail to print the following:

hostsignature(host) = records

Here, host is the host that was looked up with DNS. The records is a colon-delimited list of MX records for that host. That list might contain only the original hostname if no MX records were found.

37.5.61 -d17.9

Show randomizing MX records

MX records have preferences. Delivery is to the record with the lowest preference first, then to each higher preference, in turn, until a delivery succeeds. When two or more preferences are equal, V8 sendmail randomizes them so that they are tried in a different order. The order is the same each time, so this is really a pseudo-randomization (actually a hash function).

The -d17.9 debugging switch causes sendmail to print the following each time it randomizes:

mxrand(host) = hash

This shows that the MX records for host have been given a hash value of hash.

37.5.62 -d18.1

Show SMTP replies

The process of transmitting (or receiving) a mail message using the SMTP protocol requires sendmail to send replies as its side of the dialogue. The -d18.1 (a.k.a. -d18) debugging switch causes sendmail to print each reply that it sends. It prefixes what it prints with three right angle brackets:

>>> RCPT To: gw@wash.dc.gov

Note that this is the same output as produced with the -v command-line switch (see Section 36.7.41, -v).

The -d18.1 debugging switch also causes the following message to be printed to the standard output if the file descriptor for the connection is NULL:

smtpmessage: NULL mci_out

Prior to opening the connection, the -d18.1 debugging switch causes sendmail to print:

smtpinit output of mci_dump() here

Finally, the -d18.1 debugging switch causes sendmail to print:

reply

Each time it enters its reply() routine.

37.5.63 -d18.2

Show entry to MAIL From:

The -d18.2 debugging switch causes sendmail to show processing of the SMTP MAIL From: command that the local machine will send.

smtpmailfrom: CurHost=host

Here, host is the name of the current host that sendmail is dealing with.

37.5.64 -d18.100

Pause on SMTP read error

The -d18.100 debugging switch causes sendmail to pause(2) after a read error when processing the SMTP dialog. The administrator can then use ps(8) and gcore(8) to produce a core dump, which can then be examined with a debugger to determine the reason for the read error.

37.5.65 -d19.1

Show ESMTP MAIL and RCPT parameters

Under Extended SMTP (ESMTP) the MAIL and RCPT command can be followed by other optional parameters. The -d19.1 (a.k.a. -d19) debugging switch displays those parameters. We discuss the MAIL command first, then the RCPT command.

37.5.65.1 Show MAIL parameters

The sendmail program recognizes four parameters that can follow the address in the SMTP MAIL command: [4] SIZE, which specifies the size in bytes of the incoming message; BODY, which specifies the nature of the message body (8bitmime or 7bit); ENVID, which is used to propagate a sender-specific unique identifier for the envelope; and RET, which specifies whether or not to return the message body on an error return.

[4] SIZE is defined in RFC1653, BODY is defined in RFC1652, and ENVID and RET are defined in RFC1891.

The -d19.1 debugging switch causes sendmail to print the parameters it received:

MAIL: got arg param="value"

The param is one of the parameters shown above. The nature of the value depends on the param

The value for SIZE is a positive integer. If SIZE lacks a value, this error is issued:

501 SIZE requires a value

When multiple, illegal SIZE values are specified, the last is the one whose value is used.

The value for BODY is a case-insensitive string. It can either be 8bitmime or 7bit. If BODY lacks a value, the following error is issued:

501 BODY requires a value

If BODY has neither of the approved strings as its value, the following error is issued:

501 Unknown BODY type bad string here

When multiple, illegal BODY values are specified, the last is the one whose value is used.

The value for ENVID is a special envelope identifier. It is composed of ASCII characters in the range ! through ~, excepting + and =. Characters outside that range and those two excepted characters are replaced with a + followed by a hexadecimal representation of the character's value (there must be exactly two hexadecimal digits). If ENVID lacks a value, the following error is issued:

501 ENVID requires a value

If the text of the value is not as described above, the following error is issued:

501 Syntax error in ENVID parameter value

If more than one ENVID specified is for a given envelope, the second results in this error:

501 Duplicate ENVID parameter

The value for RET is one of two possible case-insensitive strings: hdrs tells sendmail to return only the headers of a bounced mail message; full tells sendmail to return the headers and body of a bounced mail message. If no string is present, the following error is issued:

501 RET requires a value

If a string is present but is something other than hdrs or full, the following is printed:

501 Bad argument bad string here

If more than one RET is specified for a given envelope, the following error is printed:

501 Duplicate RET parameter

If the parameter is not SIZE, BODY, ENVID, or RET, the following error is issued:

501 param parameter unrecognized

37.5.65.2 Show RCPT parameters

The sendmail program recognizes two parameters that can follow the address in the SMTP RCPT command: NOTIFY, which specifies when to notify the sender; and ORCPT, which specifies the original recipient's address.

The -d19.1 debugging switch causes sendmail to print the parameters it received:

RCPT: got arg param="value"

The param is one of the parameters shown above. The nature of the value depends on the param

The value for NOTIFY is either NEVER or a comma-separated list composed of SUCCESS, which means to notify the sender upon final delivery that the message was successfully delivered; FAILURE, which means to notify the sender if the message cannot be delivered; and DELAY, which means to notify the sender if the message is delayed. If there is no value, the following error is issued:

501 NOTIFY requires a value

If a value is present but it is not one of the words shown above, the following error is issued:

501 Bad argument \"bad value here\"  to NOTIFY

Multiple, illegal NOTIFY parameters in an envelope cause the subsequent values to be logically OR'd together.

The value for ORCPT is an address followed by a semicolon, then an address that is encoded in the same way as the envelope identifier described for ENVID above. If that value is missing, the following error message is issued:

501 ORCPT requires a value

If the value is syntactically wrong (i.e., if the value does not have a valid address following the semicolon), this error message is issued:

501 Syntax error in ORCPT parameter value

If multiple ORCPT values are specified, the second one results in this error:

501 Duplicate ORCPT parameter

37.5.66 -d20.1

Show resolving delivery agent: parseaddr()

(useful)

The -d20.1 (a.k.a. -d20) debugging switch causes sendmail to print each recipient address before it is rewritten by rule sets 3 and 0:

-parseaddr(addr)

Here, addr is the recipient address before it is rewritten and before any aliasing has been performed on it.

The -d20.1 debugging switch also causes sendmail to print information about problems that may exist in recipient addresses. If an address contains any control character that is not an isspace(3) character, sendmail prints the following message and skips that address:

parseaddr->bad address

If an address is empty (that is, if it is composed entirely of an RFC822-style comment), sendmail prints the following and skips that address:

parseaddr->NULL

After the recipient address has been rewritten by rule sets 3 and 0, and if a delivery agent was successfully selected, sendmail prints the result using the printaddr() routine.

Note that -d21 can be used to watch the rule sets parse the address, and -d24 can be used to watch the resulting tokens being pasted back together.

37.5.67 -d21.1

Trace rewriting rules

(useful)

The -d21.1 (a.k.a. -d21) debugging switch causes sendmail to print each step that it takes in rewriting addresses with rules. The -d21.1 debugging switch causes output to be produced that is identical to the output produced by the -bt command-line switch (see Section 38.1, "Overview"):

rewrite: rule set num   input: addr
rewrite: rule set num returns: addr

Here, num is the rule-set number, and addr is, first, the address (workspace) before rewriting and, second, the address after rewriting.

Because rules are recursive by nature, they can sometimes cause infinite loops (see Section 28.6.2, "Rewrite Once Prefix: $:"). When a rule loops more than 100 times, the following error is issued:

Infinite loop in rule set num, rule rnum

If the -d21.1 debugging switch was also invoked the above error is followed by:

workspace: state of rewritten address so far, here

37.5.68 -d21.2

Trace $& macros

(useful)

The -d21.2 debugging switch tells sendmail to show the current value of any deferred-expansion macro (one that was declared with the $& prefix). Each such macro that is encountered in processing a rule prints as:

rewrite: LHS $&char => "value"
rewrite: RHS $&char => "value"

The char is the single-character name of the macro, and the value is its current value. If that particular macro lacks a value, it will print as (NULL). The LHS refers to the left-hand side of the rule, and the RHS corresponds to the right-hand side. Deferred-expansion macros are described in Section 31.5.3, "Use Value as Is with $&".

37.5.69 -d21.3

Show subroutine calls

The -d21.3 debugging switch causes sendmail to print the rule-set number of each rule set called as a subroutine. Rule sets are called as subroutines by using the $> rewrite-operator in the RHS of rules (see Section 28.6.4, "Rewrite Through Another Rule Set: $>set"). The output produced looks like this:

---callsubr rset

Here, rset is the text that was interpreted as the number of the rule set, rather than the numeric value. If the number in the configuration file was a symbolic name, then that symbolic name is printed. (See Section 28.6.4 for more details about the $> rewrite-operator.)

37.5.70 -d21.4

Result after rewriting by a rule

If the LHS of a rule matches the workspace, the workspace is rewritten by the RHS of that rule. The -d21.4 debugging switch causes sendmail to print the result of a successful rewrite:

rewritten as: addr

Note that the rewritten address (addr) may be the result of rewriting by a subroutine call.

37.5.71 -d21.10

Announce failure

If the LHS of a rule fails to match the workspace, the -d21.10 debugging switch causes sendmail to print:

--- rule fails

37.5.72 -d21.12

Announce success and show LHS

If the LHS of a rule matches the workspace, the -d21.12 debugging switch causes sendmail to print:

--- rule matches

The -d21.12 debugging switch also causes the LHS of each rule to be printed before it is tried:

---trying rule: lhs

Remember that rules are pre-expanded when the configuration file is read. As a consequence, defined macros appear as their values in the lhs, rather than in their $letter form.

37.5.73 -d21.15

Show $digit replacement

The -d21.15 debugging switch causes sendmail to print each replacement that is the result of a $digit rewrite-operator in the RHS:

$digit: hex=token ...

Here, $digit is followed by one or more hex=token pairs. The hex is the address in memory of the token, and the token is the token from the LHS that is being copied into the workspace. This output can run to many screens.

37.5.74 -d21.35

Show token by token LHS matching

In addition to the rewriting information shown by the debugging switches mentioned above, the -d21.35 debugging switch also shows each and every attempt by the LHS to match the workspace. Each comparison is printed like this:

ap=workspace rp=operator

Here, ap (for address part) indicates the token in the workspace that the rule is currently trying to match. The rp (for rule part) is the operator or token at this point in the LHS that is trying to match the workspace. Note that the workspace is a single token from the workspace, and the operator is a single operator or token from the LHS of the current rule. A complete comparison of the LHS to the workspace can produce several lines of output for each rule. This output can be useful for understanding how the pattern-matching algorithm works.

The -d21.35 debugging switch also shows the index advancing to the next operator and what the corresponding state of the workspace is at that time.

ADVANCE rp=operator ap=workspace

This is useful for watching the left-hand side trying to find a match.

37.5.75 -d21.36

Trace class matching in the LHS

The -d21.36 debugging switch causes sendmail to print the following each time it finds a match for either the $= or $~ class-operator:

CLMATCH

The -d21.36 switch also shows how sendmail extends the token in the workspace and tries again, should a match for any operator fail. That is, for all operators (not just $= or $~), if the workspace contained usa.edu, sendmail would first look up usa, then usa., and finally usa.edu. Each such attempt prints as:

EXTEND rp=operator ap=workspace

If there is still no match, sendmail has to back up and try a different tack. In the case of usa.edu it would back up to the dot. For example, if it were trying $=X, the output would look like this:

BACKUP  rp=$=X, ap=.

37.5.76 -d22.1

Trace tokenizing an address: prescan()

(useful)

Processing of rules requires that all addresses be divided into tokens. The -d22.1 (a.k.a. -d22) debugging switch causes sendmail to print the various steps it takes in tokenizing an address.

In addition to tokenizing, the prescan() routine also normalizes addresses. That is, it removes RFC822-style comments and recognizes quoted strings. Be aware that rules are also viewed as addresses and processed by prescan() when the configuration file is being read.

The -d22.1 debugging switch tells sendmail to complain if the first token in the address it is parsing turns out to be nothing

prescan: null leading token

This can happen if an address (or rule) contains only RFC822-style comments in parenthesis.

37.5.77 -d22.11

Show address before prescan

(useful)

The -d22.11 debugging switch causes the address to be printed as it appears before any tokenizing or normalization:

prescan: addr

37.5.78 -d22.12

Show address after prescan

(useful)

The -d22.12 debugging switch causes the address to be printed as it appears after all tokenizing and normalization:

prescan==> addr

37.5.79 -d22.36

Show each token

The -d22.36 debugging switch causes each token to be printed when found:

tok=token

37.5.80 -d22.101

Trace low-level state machine

For the purpose of tokenizing, an address is viewed as a stream of characters. The process of tokenizing and normalizing is driven by a state machine that handles the stream one character at a time. For example, if the current character is @, sendmail sees that it has found both the start and end of a token and so resets its state to begin looking for a new token. But if the current character is a and sendmail is currently gathering a token, it knows that it should continue to gather. The use of a state machine enables sendmail to easily keep track of things such as the nesting level of angle brackets and whether or not a quoted string is present.

The -d22.101 debugging switch causes sendmail to output two lines of information. The first shows entry into a state (or continuation of a state):

c=char, s=state;

Here, char is the current character in the stream of characters that makes up the original address. The state is a two-digit octal representation of the current state. The first digit modifies the second and is a 2 (which means that this is a meta-character so don't pass it through), a 4 (which means to break the token at this character), or a 6 (which means both 2 and 4). The second digit indicates the state. The list of states and their meanings are shown in Table 37.9. The semicolon separates this output from the rest of the line that is printed below.

Table 37.9: States Used by parseaddr() to Tokenize Addresses
DecimalOctalNameDescription
000OPRA wildcard operator (such as $*)
101ATMAn atom (text token)
202QSTInside a quoted string
303SPCChewing up spaces
404ONEPick up one character
504ILLIllegal character

The rest of the output produced by the -d22.101 debugging switch shows the state changing to a new state:

ns=nstate

Here, nstate is the new state number, printed in octal with a leading zero.

Note that the level 101 in -d22.101 means that this debugging output is for true experts only.

37.5.81 -d24.4

Trace address allocation

The -d24.4 debugging switch [5] tells sendmail to print a message upon its entry into the allocaddr() routine:

[5] There is no -d24.1 information.

allocaddr(flags=flags, paddr=paddr)

Here, the address in paddr will be copied into another address (not shown). The flags is a hexadecimal representation of the RF_ flags used by sendmail to communicate with some of its internal routines. The meanings of the bits in these flags are shown in Table 37.10.

Table 37.10: sendmail's Internal RF_ flags
HexNameDescription
000RF_COPYNONEDon't copy anything
001RF_SENDERADDRSet = sender address, otherwise recipient
002RF_HEADERADDRSet = header address, otherwise envelope
004RF_CANONICALStrip RFC822 comments
008RF_ADDDOMAINOkay to append a domain
010RF_COPYPARSECopy parsed user and host
020RF_COPYPADDRCopy the print address

If RF_COPYPARSE is set in flags, the temporary strings for the host and user in the passed address (not shown) are allocated permanent storage in memory.

37.5.82 -d24.5

Trace assembly of tokens

The -d24.5 debugging switch tells sendmail to print a message upon its entry into the buildaddr() routine.

buildaddr, flags=flags, tv=tokens

The buildaddr() routine takes an array of separate tokens and pastes them back together again. The flags are ORed together hexadecimal values as documented in Table 37.10. The RF_SENDERADDR and RF_HEADERADDR flags tell buildaddr() which rewriting rules to use in processing the address.

The array of tokens being assembled is printed on a single line, each separated from the other by a space.

37.5.83 -d24.6

Show result of buildaddr()

The -d24.6 debugging switch tells sendmail to print the result of buildaddr()'s attempt to reconstruct an address.

buildaddr => output of printaddr() here (see Section 37.3.1)

37.5.84 -d25.1

Trace "sendtolist"

(useful)

Each recipient address for a mail message is added one-by-one to an internal list of recipients. The -d25.1 (a.k.a. -d25) debugging switch causes sendmail to print each address as it is added to this list:

sendto: list
   ctladdr= output of printaddr() here (see Section 37.3.1)

After each is added, those that have selected a delivery agent with the F=A (see Section 30.8.12, F=A) and F=w (see Section 30.8.43, F=w) flags set are further processed by aliasing and by reading the user's ~/.forward file. Each new address that results from this processing is added to the list, and any duplicates are discarded.

37.5.85 -d26.1

Trace recipient queueing

(useful)

The -d26.1 (a.k.a. -d26) debugging switch causes sendmail to print the addresses of recipients as they are added to the send queue - an internal list of addresses that sendmail uses to sort and remove duplicates from the recipient addresses for a mail message.

On entry to the recipient() routine, the -d26.1 debugging switch causes sendmail to print the raw address (as it appears before adding it to the send queue):

recipient (level): output of printaddr() here (see Section 37.3.1)

An address can be the result of alias expansion. Because the process of aliasing (including :include: and .forward files) can be recursive, it is possible to get too many alias expansions. The level shows the number of alias expansions so far. If that number exceeds MaxAliasRecursion (as hard coded in conf.c as 10), sendmail issues this warning:

aliasing/forwarding loop broken (level aliases deep; MAXRCRSN max)

Next sendmail compares the new address to others that are already in the send queue. If it finds a duplicate, it prints the following message and skips the new address:

addr in sendq: output of printaddr() here (see Section 37.3.1)

Here, addr is the duplicate address. Information about that address is produced with the printaddr() routine.

37.5.86 -d26.8

Trace self destructing addresses

Certain addresses can "self destruct" because they can cause an endless loop. Consider the address A. If A is aliased to B and B is aliased to A, A is a self-destructive address. The -d26.8 debugging switch causes sendmail to print the address that is being tested for self-destruction:

testselfdestruct: output of printaddr() here (see Section 37.3.1)

37.5.87 -d26.10

Show full send queue in testselfdestruct

The -d26.10 debugging switch causes the entire send queue to be printed after the testselfdestruct above:

SENDQ:
output of printaddr() here (see Section 37.3.1)
--

37.5.88 -d27.1

Trace aliasing

(useful)

The -d27.1 (a.k.a. -d27) debugging switch causes sendmail to print each step it takes when processing local addresses through aliasing. First, sendmail prints the addresses being aliased:

alias(addr)

Here, addr is the address (usually a local username) that is about to be aliased. Note that it may already be the result of previous aliasing. If the addr can be aliased, its transformation is printed as:

addr (host, user) aliased to newaddr

Here, addr is the address before aliasing, and the newaddr is the new address that resulted from successful aliasing. The host and user are the hostname and username from the recipient part of the envelope. If the addr cannot be aliased, nothing is printed.

During initialization, if the aliases database cannot be opened, the -d27.1 debugging switch causes sendmail to print:

Can't open aliasfile

Here, aliasfile is the full pathname of the aliases(5) file, as declared by the AliasFile (A) option (see Section 34.8.1, AliasFile (A)) or implied with the service-switch file and the ServiceSwitchFile option (see Section 34.8.61).

If the failure was due to a faulty map declaration, sendmail logs the following error:

setalias: unknown alias class mapclass

If the map is not one that is allowed to provide alias services, sendmail logs this error:

setalias: map class mapclass can't handle aliases

If sendmail is trying to create a database file and it can't (usually when it is run with the -bi command-line switch or run as newaliases), the -d27.1 debugging switch causes the following error to be printed:

Can't create database for filename: reason here

A self-destructive alias can cause a dangerous loop to occur. For example, the following two aliases can lead to a loop on the host mailhost:

jake:           Jake_Bair
Jake_Bair:      jake@mailhost

The -d27.1 debugging switch causes the following message to be printed when sendmail tests an address to see whether it loops:

self_reference(addr)
        ... no self ref                    <-if it didn't loop
        ... cannot break loop for "addr"   <-if it's unbreakable

An alias loop is unbreakable if no local username can be found in the list of aliases.

The -d27.1 debugging switch also causes sendmail to print the following message when it is attempting to read the user's ~/.forward file:

forward(user)

If the user has no home directory listed in the passwd(5) file, sendmail issues the following message with a syslog(3) level of LOG_CRIT:

forward: no home

The -d27.1 debugging switch also causes sendmail to print a warning if it cannot open or lock an alias file for automatic rebuilding (see Section 34.8.4, AutoRebuildAliases (D), the AutoRebuildAliases (D) option):

Can't open file:  reason here
newaliases: cannot open file:  reason here

Here, the error might be caused by the file simply not existing (as would be the case if it was NSF-mounted on a down host) or an I/O error (as would be the case for a bad disk).

warning: cannot lock file:  reason here

Failure to lock can be caused by system errors or by the file being read-only. Note that maintaining an aliases file under revision control can cause a read-only copy to exist, resulting in the following error:

Can't create database for file:  reason here
Cannot create database for alias file file

This error indicates that the output file (the dbm(3) or db(3) file) could not be created or written.

37.5.89 -d27.2

Include file, self reference, error on home

(useful)

The -d27.2 debugging switch causes each :include: and .forward filename to be printed before each is opened for reading:

include(file)

The -d27.2 debugging switch also causes additional information to be printed for the alias loop check described above:

self_reference(addr)
        ... getpwnam(user)...found     <-if in passwd file
        ... getpwnam(user)...failed    <- otherwise

The -d27.2 debugging switch also causes sendmail to print a message every time it sleeps while waiting for the aliases database to be rebuilt:

aliaswait: sleeping for sec seconds

Also, when processing the ~/.forward file, sendmail may experience a temporary inability to read it (such as when an NFS server is down). In that case the -d27.2 debugging switch causes the following message to be printed:

forward: transient error on home

Here the message will be queued and tried again later.

37.5.90 -d27.3

Forwarding path and alias wait

(useful)

The -d27.3 debugging switch causes each path for a possible .forward file to be printed before it is tried:

forward: trying file

Here, file is each file in the path of files declared by the ForwardPath (J) option (see Section 34.8.27, ForwardPath (J)).

The -d27.3 debugging switch also causes sendmail to trace its wait for another alias rebuild to complete (see Section 24.5.1, "Rebuild the Alias Database"). First sendmail prints the class (such as hash) and filename for which it will wait:

aliaswait(class:file)

If the database is not rebuildable (as would be the case with a network map class like nis, nis+, or hesiod), the -d27.3 debugging switch causes the following to be printed:

aliaswait: not rebuildable

If the file specified doesn't exist, the -d27.3 debugging switch prints

aliaswait: no source file

The -d27.3 debugging switch also causes sendmail to print an error message if there was a read error while processing a :include: or .forward file:

include: read error: reason here

37.5.91 -d27.4

Print not safe

(useful)

A ~/.forward file must be owned by the user or by root. If it is not, it is considered unsafe, and sendmail ignores it. The -d27.4 debugging switch causes sendmail to print a message describing any such file it finds unsafe:

include: not safe (uid=uid)

Note that a file is considered unsafe if, among other things, it lacks all read permissions.

The -d27.4 debugging switch also causes sendmail to print information about a :include: file beyond that printed with -d27.2 above:

include(file)             <- printed with -d27.2
   ruid=ruid euid=euid    <- printed with -d27.4

This shows the real userID (ruid) and effective userID (euid) of the current running sendmail.

The -d27.4 debugging switch also causes sendmail to print an error if a :include: or ~/.forward file cannot be opened for reading:

include: open: reason here

37.5.92 -d27.5

Trace aliasing with printaddr()

The -d27.5 debugging switch tells sendmail to print several addresses with printaddr() (see Section 37.3.1) as each one is handled.

When an address is aliased to another, the original needs to be marked as one that shouldn't be delivered. The QDONTSEND below means just that:

alias: QDONTSEND output of printaddr() here (see Section 37.3.1)

If there was a self-reference, the retained address is printed like this:

sendtolist: QSELFREF output of printaddr() here (see Section 37.3.1)

If the original (before the test for a self-reference) is not the same as the retained address, the original must be marked for nondelivery:

sendtolist: QDONTSEND output of printaddr() here (see Section 37.3.1)

If an address resulted from a :include: or ~/.forward file, it will have a controlling user associated with it. That controlling user's address needs to be marked for nondelivery:

include: QDONTSEND output of printaddr() here (see Section 37.3.1)

37.5.93 -d27.8

Show setting up an alias map

The -d27.8 debugging switch tells sendmail to print the string passed to its internal setalias() routine.

setalias(what)

Here, what is one of the items listed with the AliasFile (A) option (see Section 34.8.1), such as /etc/aliases, or implied with the service-switch file and the ServiceSwitchFile option (see Section 34.8.61).

37.5.94 -d27.9

Show uid/gid changes with :include: reads

(useful)

The -d27.9 debugging switch causes sendmail to trace the setting and resetting of its uid and gid identities when processing :include: and ~/.forward files. First an additional line is printed below the output of the -d27.2 and -d27.4 debugging switches:

include(file)             <- printed with -d27.2
   ruid=ruid euid=euid    <- printed with -d27.4
include: old uid = ruid/euid

The second and third lines above both contain the same information. After the new line is printed, sendmail may or may not change its identity depending on the nature of a :include: or ~/.forward file and that file's controlling user. Whether it changed or not, sendmail prints:

include: new uid = ruid/euid

After sendmail has finished processing a :include: or ~/.forward file, it resets its uid and gid back to their original values and displays the result:

include: reset uid = ruid/euid

37.5.95 -d27.14

Show controlling user that caused change in identity

The -d27.14 debugging switch causes sendmail to print the controlling user's address that led to the changing of the uid and gid or the currently running process:

include(file)                 <- printed with -d27.2
   ruid=ruid euid=euid        <- printed with -d27.4
ctladdr addr                  <- output of printaddr() produced with this -d27.14
include: old uid = ruid/euid  <- printed with -d27.9

The output of the printaddr() routine is described in Section 37.3.1.

37.5.96 -d27.20

Show how alias will be looked up in a map

The -d27.20 debugging switch causes sendmail to show how it is about to look up an alias in one of its database maps:

setalias(what)       <- printed with -d27.8
   map class:map what

Here, class is the type of map being looked up, such as hash or implicit (see Section 33.3, "The K Configuration Command"). The map is the map name, such as Alias0. The what is one of the items listed with the AliasFile (A) option (see Section 34.8.1), such as /etc/aliases, or implied with the service-switch file and the ServiceSwitchFile option (see Section 34.8.61).

37.5.97 -d28.1

Trace user database transactions

(useful)

The sendmail program can be compiled to use the user database (see Section 33.5, "The User Database") by defining USERDB in the Makefile (see Section 18.8.54, USERDB). If an address is selected by rule set 0 for delivery by a delivery agent with the F=l flag set, and if it remains unaliased even if the F=A flag is set, it is looked up in the user database. The -d28.1 (a.k.a. -d28) debugging switch is used to watch the interaction between sendmail and the user database:

udbexpand(addr)

Here, addr is the address being looked up.

The sender is looked up in a similar fashion. The intent in this case is to correct information such as the return address:

udbmatch(login, what)

Here, login is the login name of the sender and what is the mailname for sender lookups. If the lookup is via hesiod, sendmail will print the same information like this:

hes_udb_get(login, what)

If the sender is found in the database, sendmail prints:

udbmatch ==> login@defaulthost

Here, login may be a new login name. The defaulthost is either the sitewide host for all reply mail as defined in the user database or the default destination host for a particular user.

In the event that a db(3) style user database fails to open, the -d28.1 debugging switch displays the following error message:

dbopen(database):  reason for failure here

37.5.98 -d28.2

Show no match

The -d28.2 debugging switch causes sendmail to print any failures in lookups:

udbmatch: no match on login (length) via method

This shows that the name login was looked up with a particular length, using the database method, where method is either db or hesiod.

37.5.99 -d28.4

Show result of lookup

The -d28.4 debugging switch causes sendmail to print the result of its attempt to open (initialize) each database. There are three possible results:

  1. If a file on the local machine contains the information sought, sendmail prints

    FETCH: file fname

    Here, fname is the name of the local file.

  2. If a mail message should be sent to another host for delivery, sendmail prints:

    FORWARD: host hostname

    Here, hostname is the full canonical name of the host that takes delivery.

  3. An unknown result causes the address to remain unchanged and the following message to be printed:

    UNKNOWN

37.5.100 -d28.8

Try hes-getmailhost()

If sendmail is compiled with HES_GETMAILHOST defined (see Section 18.8.11, HES-GETMAILHOST), the following is printed when the -d28.8 debugging switch is used:

udbmatch: no match on login (length)  <- from -d28.2
  ... trying hes_getmailhost (login)
udbexpand: hesiod-getmail login stat err

Here, hes_getmailhost() is called to retrieve the name of the post office that handles this login. If that call fails, the last line is printed, showing that the hesiod error err occurred.

37.5.101 -d28.16

MX records for forward host

If a lookup is for a forwarding host (FORWARD above) and the forwarding host has MX records, the -d28.16 debugging switch causes those records to be printed:

getmxrr(host): number
    first MX record here
    second MX record here
    etc.

Here, host is the name of the host to which the lookup is forwarded. The number is the number of MX records found. That line is then followed by number MX records for that host.

37.5.102 -d28.20

Show udb lookup

The internal udb_map_lookup() routine is called each time anything is looked up in the udb database. Upon entry into that routine, the -d28.20 debugging switch causes sendmail to print

udb_map_lookup(name, what)

Here, the what is key about to be looked up in the map named name. This routine in turn calls udbmatch(). Note that the -d38.20 debugging switch also produces this output.

37.5.103 -d28.80

Preview lookups

The -d28.80 debugging switch causes sendmail to show what it is about to lookup.

udbexpand: trying login (length) via method

This shows that the name login was looked up with a particular length, using the database method, where method is either db or hesiod.

The -d28.80 debugging switch also causes the result of a lookup to be displayed:

udbexpand: match login: result

Here, login was found, and the lookup returned result.

The -d28.80 debugging switch also causes the result of hes_udb_get() to be displayed:

hes_udb_get(login, what)            <- printed with -d28.1
hes_udb_get => result               <- printed with -d28.80

Here, the hesiod library routine hes_resolve(3) is called with the two arguments login and what. The result (a string) is printed on the second line.

37.5.104 -d29.1

Special rewrite of local recipient

With a level 2 or greater configuration file (see the V configuration command in Section 27.5, "The V Configuration Command"), V8 sendmail passes the user part ($u) of local recipient addresses through rule set 5 as a hook to select a new delivery agent. Rule set 5 is called if the address is unchanged after all aliasing (including the ~/.forward file). The -d29.1 (a.k.a. -d29) debugging switch causes the address to be printed as it appears before the rule set 5 rewrite:

maplocaluser: output of printaddr() here (see Section 37.3.1)

Information about the address is printed with the printaddr() routine. The output of maplocaluser() becomes the input to recipient(), so the result of rewriting can be seen by using the -d26.1 debugging switch in combination with this one.

Note that the particulars about whether or not an address will be processed by rule set 5 are described in -d29.5 below.

37.5.105 -d29.4

Trace fuzzy matching

(useful)

Fuzzy matching is the attempt to match a local recipient name to one of the names in the gecos field of the passwd(5) file (or NIS map). The -d29.4 debugging switch causes the process of fuzzy matching to be traced:

finduser(name)

Here, name is an address in the form of a local user address, without the host part. The name is first looked up in the passwd(5) file on the assumption that it is a login name. If it is found, sendmail prints

found (non-fuzzy)

If sendmail was compiled with hesiod support, all numeric login names will not work properly, resulting in the following:

failed (numeric input)

If the name is looked up and not found, the entire passwd(5) is searched, to see whether name appears in any of the gecos fields. This search is done only if MATCHGECOS (see Section 18.8.18, MATCHGECOS) was defined when sendmail was compiled and if the MatchGECOS (G) option (see Section 34.8.34, MatchGECOS (G)) is true. If MATCHGECOS was undefined, the search ends and the not-found name causes the mail to bounce. If the MatchGecos (G) option is false, sendmail bounces the message and prints the following:

not found (fuzzy disabled)

If the MatchGecos (G) option is true, the gecos fields are searched. But before the search starts, any underscore characters (and the character defined by the BlankSub (B) option; see Section 34.8.5, BlankSub (B)) that appear in name are converted to spaces. Then, in turn, each gecos field has the full name extracted (everything following the first comma, semicolon, or percent is truncated off, including that character), and any & characters found are converted to the login name. The two are then compared in a case-insensitive fashion. If they are identical, sendmail prints:

fuzzy matches gecos

If all gecos fields are compared and no match is found, sendmail bounces the message and prints the following:

no fuzzy match found

There is no debugging flag to watch each comparison.

37.5.106 -d29.5

Preview rule set 5

The -d29.5 debugging switch causes sendmail to print an address just before it is tested to see whether rule set 5 should be called:

recipient: testing local?  cl=level, rr5=addr,
                                               -^
                                         output of printaddr() here (see Section 37.3.1)

For the address to be rewritten, the configuration file version as displayed by level must be 2 or more, the address in memory for rule set 5 (shown with rr5) must be nonzero, the flags in addr must not contain QNOTREMOTE, QDONTSEND, QQUEUEUP, or QVERIFIED, and the delivery agent for the address must have the F=5 flag set.

The -d29.5 debugging switch also causes sendmail to display the following if the address is rewritten by rule set 5:

maplocaluser: QDONTSEND output of printaddr() here (see Section 37.3.1)

Here the printaddr() routine prints the old address that is being canceled.

37.5.107 -d29.7

Show over-aliasing fuzzy fallback

If a fuzzy match causes more than three transformations to occur during aliasing, sendmail emits the following error:

aliasing/forwarding loop for login broken

Here, login is the login name of the recipient that started the suspected runaway aliasing. The -d29.5 debugging switch also causes sendmail to print that it is trying to fall back to the original login name for delivery:

at trylocaluser login

Note that this message is printed before the message printed by the -d26 switch (which shows the testing for a self-destructive addresses).

37.5.108 -d30

Trace processing of header

When sendmail reads a mail message, it first collects (reads) the header portions of that message (everything up to the first blank line) and places the result into a temporary file in the queue directory. While it is processing the header, if the SaveFromLine (f) option (see Section 34.8.59, SaveFromLine (f)), is false, the UNIX-style "From " header is removed, and the important information in it is saved for later use.

The -d30.1 (a.k.a. -d30) debugging switch causes sendmail to print the following succinct message when it finds the end of the header portion of a mail message:

EOH

If end-of-headers was caused by a read error or a broken connection, sendmail prints:

collect: premature EOM:  reason for failure here

If end-of-headers was caused by a Message: or Text: header, then the rest of the header portion of the message is ignored.

The -d30.2 debugging switch first causes sendmail to print its entry into collect():

collect

Then, when sendmail strips (eats) the UNIX-style, five-character "From " header from a mail message, it tries to extract (and save) the date from the header. The -d30.2 debugging switch causes sendmail to print the field portion of the header as it appears before the date is extracted:

eatfrom(field)

The eatfrom() routine will vanish if NOTUNIX (see Section 18.8.32, NOTUNIX) is defined when compiling sendmail.

37.5.110 -d30.3

Show a to-less header being added

If the header of a mail message lacks recipient information (lacks all of the To:, Cc:, Bcc:, and Apparently-To: header lines), then sendmail adds a header as defined by the NoRecipientAction option (see Section 34.8.43, NoRecipientAction). The -d30.3 debugging switch causes sendmail to print which header it is adding:

Adding header: recipient

Here, header is the text of the header being saved, and recipient is the address of the recipient as taken from the envelope of the message.

37.5.111 -d30.35

Trace collect states

The process of collecting the message header and body over an SMTP connection is driven by a state engine inside sendmail. The -d30.35 debugging switch causes sendmail to display each state just before it is processed:

top, istate=is, mstate=ms

Here, is is the current input state as described in Table 37.11 and ms is the current message state as described in Table 37.12.

Table 37.11: collect() Input States
istateNameDescription
0IS_NORMCurrently in middle of a line
1IS_BOLCurrently at beginning of a line
2IS_DOTJust read a dot at beginning of line
3IS_DOTCRJust read ".\r" at beginning of line
4IS_CRJust read a carriage return
Table 37.12: collect() Message States
mstateNameDescription
0MS_UFROMCurrently reading UNIX from line
1MS_HEADERCurrently reading message header
2MS_BODYCurrently reading message body

The -d30.35 debugging switch also causes the same information to be printed every time sendmail goes to a new state:

nextstate, istate=is, mstate=ms, line = "header"

Here, the extra information is the current text of the header being processed.

37.5.112 -d30.94

Trace collect states

The -d30.94 debugging switch causes sendmail to print the input state (see Table 37.11) for each character being processed:

istate=is, c=char (hex)

Each character is printed both as the character it is (char) and how it is represented in hexadecimal (hex).

37.5.113 -d31.2

Trace processing of headers

(useful)

Header lines (see Section 35.1, "The H Configuration Command") from the configuration file and from mail messages are processed by the chompheader() routine before they are included in any mail message. That routine parses each header line to save critical information, to check for validity, and to replace default values with new values.

The -d31.2 debugging switch [6] shows that sendmail is about to check whether it should replace a From: or Resent-From: header with the one defined by the H configuration command. If the configuration file is not being read and if sendmail is not processing the queue, the following test is made:

[6] There is no -d31.1 information.

comparing header from (header) against default (addr or name)

The value of the From: or Resent-From: header is compared to the sender's address (addr) and to the sender's name. If it is that same as either one, the address is replaced.

37.5.114 -d31.6

Entering chompheader()

The -d31.6 debugging switch shows each header as it appears when it enters the chompheader() routine:

chompheader: line

Here, line is the exact text of the original header before processing. Unfortunately, there is no debugging switch that allows the result of this processing to be viewed.

To determine how it should handle a header, sendmail compares each header to its list of headers in sendmail.h. The -d31.6 debugging switch also shows the result after the comparisons have been done:

no header match

header match, hi_flags= flags in hexadecimal here

The flags and their hexadecimal equivalence are shown in Table 35.2 in Section 35.5, "Header Behavior in conf.c".

37.5.115 -d32.1

Show collected headers

The -d32.1 (a.k.a. -d31) debugging switch causes sendmail to print the header lines that it collected from a received mail message:

--- collected header ---
     header lines here
--------------

Each header line is printed with the header name on the left, a colon, and the value for that header on the right. If there is no value, sendmail prints <NULL>.

If the H_DEFAULT flag is set for any header (see Section 35.5.3, "H_DEFAULT"), the value for the header is printed inside parentheses with macros unexpanded, just before it is printed in expanded form. For example,

Full-Name: ($x) Your Full Name

37.5.116 -d32.2

Show ARPA mode with setsender

The -d32.2 debugging switch works only if the mode set with the -b command-line switch is in ARPA (-ba) mode (see Section 36.7.3, -ba). It shows the sender address being extracted from the header with setsender():

eatheader: setsender(*value == realvalue)

The setsender() routine can be further traced with the -d45.1 debugging switch.

37.5.117 -d33.1

Watch crackaddr()

The crackaddr() routine's job is to find an email address amidst other nonaddress text, then to save that nonaddress part:

gw@wash.dc.gov (George Washington)  -> crackaddr() -> $g (George Washington)

The -d33.1 (a.k.a. 33) debugging switch causes sendmail to print the potential address prior to cracking and, after that, the address that it found:

crackaddr(potential)
crackaddr=>`addr'

The legal ways that addresses can be placed within other text is described in Section 35.3, "Header Field Contents". See also the /parse rule-testing command (Section 38.5.5, "Parse an Address with /parse") to put crackaddr() in context.

37.5.118 -d34.1

Watch header assembly for output

The sendmail program uses putheader() to create headers that didn't exist before. The -d34.1 (a.k.a. -d34) debugging switch causes sendmail to print the following on entry to that routine:

-- putheader, mailer = agent --

Here, agent is the symbolic name of the delivery agent that will deliver the bounced message.

37.5.119 -d34.11

Trace header generation and skipping

(useful)

Each header line created is displayed with two leading spaces. For example,

-- putheader, mailer = *file* --
  Return-Path: you

Then certain headers are excluded from the bounced mail message header. Those with the H_CTE flag set (see Section 35.5.12, "H_CTE") and either the MCIF_CVT8TO7 or MCIF_INMIME mci flags set (see Table 37.17) will have the text:

(skipped (content-transfer-encoding))

appended and that header skipped (excluded).

Any header that has both H_CHECK and H_ACHECK flags set and doesn't have identical delivery agent flags set for itself and its cached connection information will also be skipped:

(skipped)

All resent headers (those marked with H_RESENT) are also skipped:

(skipped (resent))

Return-receipt headers are also skipped:

(skipped (receipt))

If a Bcc: header (see Section 35.10.4, Bcc:) is being skipped, this is printed:

(skipped - bcc)

Finally, valueless headers are also skipped with this message:

(skipped - null value)

Any headers that survive this skipping process are included in the eventually delivered bounced message. Note that MIME headers are not generated or displayed here (see -d43).

37.5.120 -d35.9

Macro values defined

(useful)

The -d35.9 debugging switch [7] causes sendmail to print each macro as it is defined. The output looks like this:

[7] There is no -d35.1 information.

define(name as "value")

Here, the name is the macro's name, and the value is the value (text) assigned to the macro. If the macro already has a value assigned to it, sendmail prints:

redefine(name as "value")

37.5.121 -d35.14

Macro Identification

With the introduction of multicharacter macro names, it is now necessary for sendmail to convert each macro name from text form into sendmail's internal form. Single-character macro names are represented by themselves. Multicharacter names are represented by values from 0240 (octal) upward. The -d35.14 debugging switch causes sendmail to print each macro name as it is being looked up:

macid(name) => value

The name is the text immediately following a $ character, including any trailing junk in the line. For example, the following miniconfigurations file:

V7
D{FOO}foo
R$H     ${FOO}  note no $H defined

produces this output (with only the macid lines shown):

macid({FOO}foo) => 0xa0
macid(H\t${FOO}\tnote no $H defined) => H
macid({FOO}\tnote no $H defined) => 0xa0
macid(H defined) => H

37.5.122 -d35.24

Macro expansion

Macros that are included in text must be translated into values (expanded) so that the values may be used. The -d35.24 debugging switch tells sendmail to display such text both before and after the macros in it have been expanded. The "before" looks like this:

expand("text")

For example,

expand("$w.$D")

The text (here $w.$D) may be any ASCII string. In it, special characters like the newline character are printed in C language, backslash-escaped notation (such as \n). Macros are printed with either the $ prefix (such as $w above with V8 sendmail) or some other prefix (IDA uses ^Aw.^AD, SunOS uses /w./D; others use the archaic \001w.\001D notation).

Expansion is performed only on defined macros (using the $ prefix), on macro conditionals (in which one of two values is used, depending on whether a macro has a value or not, such as $?x$x$|nobody$.), and and on the $& prefix (deferred expansion).

After the first (leftmost) macro or conditional is expanded in text, sendmail prints the transformed text as follows:

expanded ==> "text"

For example,

expanded ==> "wash.$D"

If any unexpanded macros or conditionals remain in text, this expanded process is recursively repeated until everything that can be expanded has been expanded. This process of recursion allows macros to have other macros as their values.

37.5.123 -d36.5

Trace processing by stab()

The symbol table is a block of memory that contains information about all the symbolic names used by sendmail. Symbolic names are delivery agent names (such as local), aliases, database classes, hostnames, and macros. Symbols are placed into the symbol table with the stab() routine. That routine is also used to see whether a symbol has already been inserted and, if so, to obtain its value. The -d36.5 debugging switch [8] causes sendmail to print the following upon its entry into the stab() routine:

[8] There is no -d36.1 information.

STAB: name type

Here, name is the symbolic name to be inserted or looked up. The type is one of the values listed in Table 37.13.

Table 37.13: Types of Symbols Recognized by stab()
TypeMnemonicDescription
0ST_UNDEFUndefined type
1ST_CLASSClass (from C and F configuration commands)
2ST_ADDRESSAn address in parsed format
3ST_MAILERA delivery agent (from M configuration command)
4ST_ALIASAn alias, if no external database
5ST_MAPCLASSA database class (K command)
6ST_MAPFunction that handles a class
7ST_HOSTSIGHost MX signature
8ST_NAMECANONCached canonical name
9ST_MACROMacro name to id value mapping
10ST_RULESETRuleset name to number mapping
11ST_SERVICEService switch file entry
16ST_MCISMTP connection status\*[=a]

This is the base (offset) of types 16 through 16+n, where n is 16 plus MAXMAILERS as defined in conf.h. If stab() is being used to insert a symbol, the above output is concluded with:

entered

If stab() is being used to look up a symbol, one of the two following messages is printed:

not found
type type val hex hex hex hex

If it is found, four hexadecimal values are printed, which show the first four 4-byte words of the value.

37.5.124 -d36.9

Show hash bucket

A hashing algorithm is used to make the symbol table more efficient. The -d36.9 debugging switch is used to see the hash value selected for any given symbol:

(hfunc=hash)

The number of possible hash-table buckets is limited by STABSIZE, as defined in stab.c. [9]

[9] You can experiment with different hashing algorithms by modifying the code in stab.c. But note that it has already been heavily tuned in V8.7, roughly doubling its speed over that of earlier versions.

37.5.125 -d36.90

Trace function applied to all symbols

The -d36.90 debugging switch causes the name and type of each symbol to be printed as a common function is applied to each with sendmail's internal stabapply() function.

stabapply: trying type/name

The stabapply() routine is used to initialize maps and to print the members of a class.

37.5.126 -d37.1

Trace setting of options

(useful)

Options can be set on the command line or in the configuration file. The -d37.1 (a.k.a. -d37) debugging switch allows you to watch each option being defined. As each is processed, this message is first printed, without a trailing newline:

setoption: name (char).sub=val

Here, name is the option's multicharacter name, char is its single-character equivalent (or a hexadecimal value if it is non-ASCII), and sub is the subvalue for that option if there was one. Finally, val is the value being given to that option. If the option has already been set from the command line and is thus prohibited from being set in the configuration file, sendmail prints:

(ignored)

A newline is then printed, and the job is done. If defining the option is permitted, sendmail next checks to see whether it is safe. If it is not, sendmail prints:

(unsafe)

If it is unsafe, sendmail checks to see whether it should relinquish its root privilege. If so, it prints:

(Resetting uid)

A newline is then printed, and the option has been defined. Options in general and safe versus unsafe are covered in Chapter 34, Options.

37.5.127 -d37.8

Trace adding of words to a class

(useful)

The adding of words to a class (C or F configuration commands) can be traced with the -d37.8 debugging switch. Each word is printed like this:

setclass(name, text)

The text is added to the class whose symbolic name is name. Class names can be single-character or multicharacter (see Section 32.1, "Class Configuration Commands").

37.5.128 -d38.2

Show map opens and failures

(useful)

Most maps are declared directly with the K configuration command (see Section 33.3). Others are declared internally by sendmail, such as the host and alias maps. The -d38.2 debugging switch [10] first shows maps being initialized:

[10] There is no -d38.1 information.

map_init(class:name, file, pass)

Here, class is one of the internal classes allowed by sendmail, such as host, and dequote (see Section 33.3, the K configuration command). The name is either the name you gave to the map with the K configuration command or one assigned internally by sendmail (like aliases.files). The file is either NULL or the name of the database file (such as /etc/aliases). And pass is a flag that tells sendmail whether or not it should open the database, rebuild the database, or do neither.

Next the -d38.2 debugging switch causes sendmail to show each map as it is about to be opened. The output that is produced will look like one of the following lines:

bt_map_open(name, file, mode)
hash_map_open(name, file, mode)
hes_map_open(name, file, mode)
impl_map_open(name, file, mode)
ldap_map_open(name, mode)
ndbm_map_open(name, file, mode)
ni_map_open(name, file, mode)
nis_map_open(name, file, mode)
nisplus_map_open(name, file, mode)
stab_map_open(name, file, mode)
switch_map_open(name, file, mode)
text_map_open(name, file, mode)
user_map_open(name, mode)

In all of the previous lines, the mode is a decimal representation of the file permissions that are used during the open. The name prefixing each line corresponds to the class of map. For example, impl corresponds to the implicit class.

The -d38.2 debugging switch also causes sendmail to display the nis domain that was used if one was specified for the nisplus class:

nisplus_map_open(file): using domain ypdomain

The -d38.2 debugging switch also allows other silent errors to be printed about some open failures. Under nis+, lookups are performed by named columns (as in the case of the password database, the columns are named passwd, shell, and so on):

nisplus_map_open(name): can not find key column colname
nisplus_map_open(name): can not find column colname

Text files that are used as maps must be declared with a filename that is an absolute path (begins with a / character thus forming a fully qualified pathname), that exists, and that is a regular file. If there is a problem, one of the following is logged (even if -d38.2 is not specified):

text_map_open: file name required
text_map_open(file): file name must be fully qualified
text_map_open(name): can not stat file
text_map_open(name): file is not a file

Text files should be syntactically correct. The delimiting character, char, will print either as a single character or as the phrase (whitespace). Note that the third line below will be reported only when the -d38.2 debugging switch is used:

text_map_open(file): -k should specify a number, not badtext
text_map_open(file): -v should specify a number, not badtext
text_map_open(file): delimiter = char

37.5.129 -d38.3

Show passes

The sendmail program initializes maps in passes so that it can open a map for reading or rebuild. That is, pass 0 opens it for reading only, and passes 1 and 2 open it for updating. This gives sendmail the opportunity to detect optional maps. The -d38.3 debugging switch causes sendmail to print wrong pass every time it skips rebuilding because the pass is inappropriate:

map_init(class:name, file, pass)  <- from -d38.2
wrong pass

The -d38.3 debugging switch also causes sendmail to print a failure message if an implicit class map does not exist:

impl_map_open(name, file, mode)   <- from -d38.2
no map file

37.5.130 -d38.4

Show result of map open

(useful)

When rebuilding the aliases files, each database is opened before it is rebuilt or not. The -d38.4 debugging switch shows the success or failure of each open:

map_init(class:name, file, pass)  <- from -d38.2
     class:name file valid or invalid

The status is valid if the open succeeded; otherwise, it is invalid.

The -d38.4 debugging switch also shows each map being looked up in a switch class map (see Section 33.8.17, switch).

switch_map_open(name, file, mode)  <- from -d38.2
        map_stack[index] = class:name

If the name is not one that was declared in a K configuration command, the following error is printed:

Switch map class: unknown member map name

37.5.131 -d38.9

Trace map closings and appends

The -d38.9 debugging switch traces map closures for those kind of maps that can be closed:

ndbm_map_close(name, file, flags)
db_map_close(name, file, flags)
impl_map_close(name, file, flags)
prog_map_lookup(name) failed (errno) - closing
seq_map_close(name)

Here, the name is either the name you gave to the map with the K configuration command or one assigned internally by sendmail (like aliases.files). The file is the filename on disk that contains the database. The flags describe the specific features of a map. They are printed in hexadecimal, and the meanings of the values printed are listed in Table 37.14.

Table 37.14: Flags Describing Properties of Database Maps
HexTextDescription
00001MF_VALIDThis entry is valid.
00002MF_INCLNULLInclude null byte in key.
00004MF_OPTIONALDon't complain if map not found.
00008MF_NOFOLDCASEDon't fold case in keys.
00010MF_MATCHONLYDon't use the map value.
00020MF_OPENThis entry is open.
00040MF_WRITABLEOpen for writing.
00080MF_ALIASThis is an alias file.
00100MF_TRY0NULLTry with no null byte.
00200MF_TRY1NULLTry with the null byte.
00400MF_LOCKEDThis map is currently locked.
00800MF_ALIASWAITAlias map in aliaswait state.
01000MF_IMPL_HASHImplicit: underlying hash database.
02000MF_IMPL_NDBMImplicit: underlying ndbm database.
04000MF_UNSAFEDBThis map is world writable.
08000MF_APPENDAppend new entry on rebuild.
10000MF_KEEPQUOTESDon't dequote key before lookup.

In addition to tracing map closures, the -d38.9 debugging switch traces map appends allowed by the MF_APPEND flag (see Section 33.3.4.1, "-A append values for duplicate keys (V8.7 and above)") as specified when the database is declared by the K configuration command:

ndbm_map_store append=new
db_map_store append=new

Here new is new value appended to the old. Since this property is used for alias files, the new and old values have a comma inserted between them.

37.5.132 -d38.10

Trace NIS search for @:@

The NIS alias map needs to contain a @:@ entry to indicate that it is fully updated and ready for reading. But because HP-UX omits the @:@, it is useful only as a check to see whether the NIS map exists. The -d38.10 debugging switch causes the result of this check to be printed as:

nis_map_open: yp_match(@, domain, nismap)

Here, domain is the NIS domain, and nismap is usually mail.aliases (but it can be redefined in your configuration file; see Section 34.8.1). If the map is not marked as optional (see Section 33.3.4.8, "-o the database file is optional (V8.1 and above)"), the following error will be printed:

Cannot bind to map nismap in domain domain:  reason here

The -d38.10 debugging switch also traces the NIS+ open's check for a valid table.

nisplus_map_open: nisplusmap.domain is not a table

Essentially, this says that the NIS+ map nisplusmap (in the domain shown) does not exist. The error is printed even if the -o (optional) database switch (see Section 33.3.4.8) is missing.

37.5.133 -d38.12

Trace map stores

The -d38.12 debugging switch shows values being stored in maps that support updates.

db_map_store(name, key, value)
ndbm_map_store(name, key, value)
seq_map_store(name, key, value)

Here, the name is either the name you gave to the map with the K configuration command or the name assigned internally by sendmail (like aliases.files). The key is the key for which the new value is being stored, and the value is the value for that key.

37.5.134 -d38.19

Trace switch map finds

(useful)

A switched map is one that, either as the result of a service-switch file or because of sendmail's internal logic, causes lookups to follow a select path. For example, Sun's Solaris 2 nsswitch.conf might specify that aliases be looked up in the order files, then nis:

switch_map_open(name, file, mode)  <- from -d38.2
switch_map_find => nmaps
                maptype
                ...

First the number of maps found is printed with nmaps, then each type of map found in the list is printed. Each is a class name, such as files, or nis.

37.5.135 -d38.20

Trace map lookups

(useful)

The -d38.20 debugging switch traces many different map lookups. The getcanonname() routine looks up a hostname and tries to canonify it:

getcanonname(host), trying maptype
getcanonname(host), found
getcanonname(host), failed, stat=error

Here, host is the hostname that is being looked up, and maptype is one of files, nis, nisplus, dns, or netinfo. If the canonical name is not found, the error shows one of the errors listed in <sysexits.h>. The process of canonifying the name is handled by calling special subroutines based on the maptype:

text_getcanonname(host)				<- maptype is files
nis_getcanonname(host)				<- maptype is nis
nisplus_getcanoname(host), qbuf=query		<- maptype is nisplus
dns_getcanonname(host, flag)			<- maptype is dns, printed with -d8.2
ni_getcanonname(host)				<- maptype is netinfo

The nisplus_getcanoname() routine is far more verbose than the other. In addition to the information printed above, the -d38.20 switch also prints

nisplus_getcanoname(host), got count entries, all but first ignored
nisplus_getcanoname(host), found in directory "nisdir"
nisplus_getcanonname(host), found result
nisplus_getcanonname(host), failed, status=nsistatus, nsw_stat=errno

The -d38.20 debugging switch also traces general lookups in various kinds of databases. Again note that nisplus is more verbose than the others:

ndbm_map_lookup(name, key)
db_map_lookup(name, key)
nis_map_lookup(name, key)
nisplus_map_lookup(name, key)
qbuf=query
nisplus_map_lookup(key), got count entries, additional entries ignored
nisplus_map_lookup(key), found value
nisplus_map_lookup(key), failed
hes_map_lookup(name, key)
ni_map_lookup(name, key)
stab_lookup(name, key)
impl_map_lookup(name, key)
user_map_lookup(name, key)
prog_map_lookup(name, key)
prog_map_lookup(name): empty answer
seq_map_lookup(name, key)

Here, the name is either the name you gave to the map with the K configuration command or one assigned internally by sendmail (such as aliases.files). The key is the item being looked up. The file is the pathname of the file that contains the database.

37.5.136 -d38.44

Show nis-getcanonname() record

The -d38.20 debugging switch described above prints the nis lookup of the canonical hostname. This -d38.44 debugging switch prints the result of that lookup:

nis_getcanonname(host)          <- from -d38.20
got record `result\'

37.5.137 -d39.1

Display %digit database mapping

When the RHS of a rule matches an entry in a database map with $( and $), that entry replaces the key. If the entry contains %digit literals, they are replaced by corresponding $@ values in the RHS (see Section 33.4.2, "Specify Numbered Substitution with $@").

The -d39.1 (a.k.a. -d39) debugging switch causes sendmail to print the entry and any replacement values:

map_rewrite(entry), av =
       value1
       value2
       ...etc

After the RHS is rewritten (after all the $@ values have replaced all the %digit literals), sendmail prints the result:

map_rewrite => rewritten RHS here

37.5.138 -d40.1

Trace processing of the queue

The -d40.1 (a.k.a. -d40) debugging switch traces the placing of a mail message into the queue and the processing of queued files.

When a mail message is placed into the queue, its qf file is written as a tf temporary file; then that temporary file is closed and renamed to be the qf file. The -d40.1 debugging switch causes sendmail to announce that it is beginning that process by printing the queued message's identifier:

>>>>> queueing qid(new id) >>>>> 
queueing  for each recipient, output of printaddr() here (see Section 37.3.1)
<<<<< done queueing qid <<<<<

First, the queue identifier is printed (qid). If this identifier is brand-new, the phrase "(new id)" is printed. Next, sendmail prints complete information about each recipient for the message using the printaddr() routine. Finally, done queueing is printed, and the queuing of the qid item is finished.

When sendmail processes files in the queue, it first prereads all the qf files and sorts the jobs by priority. After the list has been sorted, the -d40.1 debugging switch causes sendmail to print that list, one message per line, in the following format:

qfname: pri=priority

Here, qfname is the basename of the qf file, and priority is the current priority of each message (see Section 34.8.53, RecipientFactor (y)). After the sorted list of messages has been processed, and if there are any messages in that list, sendmail attempts to deliver each of the messages in the order in which it appears in the list. The -d40.1 debugging switch causes sendmail to print the following line of information for each message processed:

dowork: (qfname)

37.5.139 -d40.3

Show envelope flags

The -d40.3 debugging switch causes the envelope flags for each message to be printed as it is queued:

>>>>> queueing qid(new id) >>>>> <- from -d40.1
  e_flags=  output of printenvflags() here

The envelope flags are described in Table 37.3 in Section 37.5.12.

37.5.140 -d40.4

Show qf file lines as they are read

The qf file is composed of individual lines of information (see Section 23.9.11, P line). The -d40.4 debugging switch causes sendmail to print each of those lines as it is read:

+++++ Xtext

Each line begins with five plus characters. The qf file's key letter (here, X) follows, then the rest of the text that made up that line. In the qf file, indented lines (lines that begin with a space or tab character) that immediately follow the key line are appended to that key line. Those joined lines are printed after they are joined. Note that the lines of the qf file are printed before they are processed by sendmail. An error in a line is printed after the line is printed.

If the queue file could not be read, the -d40.4 debugging switch instead causes sendmail to print this error:

readqf(qid) failed

Here, qid is the queue identifier for the message. Note that reading can legitimately fail if the queue file is locked. Use -d40.8 (described below) to see the exact reason for failure.

37.5.141 -d40.8

Show reasons for failure

The -d40.8 debugging switch causes sendmail to print the reason it could not process a message's qf file. One possibility is:

readqf(qfname): fopen failure (error text here)

If the failure was caused by anything other than the file's nonexistence, the following is also logged:

readqf: no control file qfname

If the qf file could not be read because it is locked by another incantation of sendmail (a valid reason), the -d40.8 debugging switch prints:

qid: locked

Here, qid is the identifier portion of the qf file. If the log level is set to greater than 19 (see the LogLevel (L) option, Section 34.8.33, LogLevel (L)), the above message will also be logged.

For security the sendmail program fstat(2)'s the qf file after it is open to make sure it cannot be fooled by a race condition. If that fstat(2) fails, the following is printed if the -d40.8 debugging switch was specified:

readqf(qid): fstat failure (error text here)

If the qf file is owned by someone other than the effective uid of sendmail, the qf file will be renamed into a Qf file (see Section 23.3, "A Bogus qf File (V8 only): Qf"). If this -d40.8 debugging switch was specified, the following message will also be printed:

readqf(qid): bogus file

The MinQueueAge option (see Section 34.8.41, MinQueueAge) determines the interval between queue runs for any given file. If a qf file was not last run at least MinQueueAge minutes ago, it is skipped and the -d40.8 debugging switch causes the following message to be printed:

qid: too young (howlong)

If the log level is set to greater than 19 (see the LogLevel (L) option, Section 34.8.33), the above message will also be logged.

37.5.142 -d40.9

Show qf and lock file descriptors

After sendmail has opened the qf file (with -d40.1) and printed the envelope flags (with -d40.3), this -d40.9 debugging switch will cause the file descriptors for the qf file and its corresponding lock file to be dumped:

>>>>> queueing qid(new id) >>>>> <- from -d40.1
 e_flags=                       <- from -d40.3
 tfp=  output of dumpfd() here
 lockfp=  output of dumpfd() here

The e_flags are described in Table 37.3 of Section 37.5.12. Here, tfp= shows the file descriptors for the qf file, and lockfp= shows the descriptors for the lock. See -d2.9 (Section 37.5.13) for a description of output of dumpfd().

37.5.143 -d40.32

Dump the send queue

The -d40.32 debugging switch causes sendmail to dump the list of message recipients:

>>>>> queueing qid(new id) >>>>> <- from -d40.1
  e_flags=                       <- from -d40.3
  sendq= <- output of printaddr()) here (see Section 37.3.1)
  tfp=                           <- from -d40.9
  lockfp=                        <- from -d40.9

37.5.144 -d41.1

Trace queue ordering

(useful)

The -d41 (a.k.a. -d41) debugging switch causes sendmail to print its ordering of the queue. First it prints

orderq:
        QueueLimitId = qid            <- if -qI used
        QueueLimitSender = sid        <- if -qS used
        QueueLimitRecipient = rid     <- if -qR used

See Section 23.6.2.3, "Process by identifier/recipient/sender: -q[ISR]" for an explanation of how the -qI, -qS, and -qR command-line switches can limit the scope of a queue run. If none of them were specified, only orderq: is printed. The -d41.1 debugging switch is extremely handy for previewing the effect of the -qI, -qS, and -qR command-line switches. When combined with -bp (mailq), these switches limit the queue listing and thus preview the effect of a limited queue run:

% mailq
                Mail Queue (1 request)
-Q-ID- -Size- ---Q-Time--- ------Sender/Recipient------
MAA11111     4560 Tue Dec 31 12:37 you
                                   you@here.us.edu
% mailq -d41.1 -qI22222
orderq:
        QueueLimitId = 22222
Mail queue is empty

The -d41.1 debugging switch also traces the growth of the queue working list. Every time the limit of that list is reached, the internal routine grow_wlist() is called to extend the list size by QUEUESEGSIZE (where QUEUESEGSIZE is described in Section 18.8.38, QUEUESEGSIZE).

grow_wlist: WorkListSize=current
grow_wlist: WorkListSize now newsize

If the log level is set to greater than 1 (see the LogLevel (L) option, Section 34.8.33), the following is also logged each time the list size grows:

grew WorkList for qdirectory to newsize

If the size could not be increased (because the program reached the limit of available memory) and if the LogLevel (L) option is greater than 0, sendmail will log this error at LOG_ALERT:

FAILED to grow WorkList for qdirectory to newsize

This message will repeat until there are no more queue entries to process after the limit is received. However, all the files that are already in the work list will be processed, so presumably the next run will catch the failed messages.

37.5.145 -d41.2

Cannot open qf

Ordinarily, sendmail is silent about failures to open a qf file, but the -d41.2 debugging switch causes it to print the reason the open failed:

orderq: cannot open qfname (reason for failure here)

Here, qfname is the name of the qf file that could not be opened.

37.5.146 -d41.49

Show excluded (skipped) queue files

The 41.49 debugging switch causes sendmail to display the queue files that were not included in the work list:

skipping qfname (bit)

Here, the bit is a hexadecimal representation of the requirement that was not met. These bits are listed in Table 37.15.

Table 37.15: Bits Describing a Queue Run's Requirements
HexMnemonicDescription
1NEED_PPriority must be high enough (required qf file line)
2NEED_TMust have been in queue long enough (required qf file line)
4NEED_RMatch a recipient
10NEED_SMatch a sender

Note that nothing will be printed if the message was skipped because its identifier did not match the -qI specification.

37.5.147 -d41.50

Show every file in the queue

The sendmail program scans the queue directory looking for all the qf files to set up its working list. If a file doesn't start with the letters "qf," it is ordinarily silently skipped. The -d41.50 debugging switch causes sendmail to display every single file it finds in its queue directory:

orderq: checking file

The file can be a directory, such as .., or a regular file, such as a df or qf file.

37.5.148 -d42.2

Show connection checking

V8 sendmail can be configured with the ConnectionCacheSize (k) option (see Section 34.8.10, ConnectionCacheSize (k)) to maintain open SMTP connections to a few other hosts. Before making a new SMTP connection, sendmail checks to see if it already has one established. The -d42.2 [11] debugging switch causes sendmail to print the result of that check.

[11] Note that there is no -d42.1 information.

mci_get(host mailer): mci_state=state, _flags=flag, _exitstat= stat, _errno=err

Here, the host is the name of the host to which the connection is to be made, and the mailer is the symbolic name of the delivery agent. The state is the status of the current SMTP connection (if there is one) as shown in Table 37.16.

Table 37.16: mci_get() Connection States
StateMnemonicDescription
0MCIS_CLOSEDNo traffic on this connection
1MCIS_OPENINGSending initial protocol
2MCIS_OPENConnection is open
3MCIS_ACTIVEMessage being sent
4MCIS_QUITINGRunning SMTP quit protocol
5MCIS_SSDSMTP service shutting down
6MCIS_ERRORI/O error on connection

The flag describes the overall status of the connection. It can have one or more values from those shown in Table 37.17 where those values are OR'd together.

Table 37.17: mci_get() Status Flags
FlagMnemonicDescription
0x0001MCIF_VALIDIf set, this entry is valid
0x0002MCIF_TEMPIf set, don't cache this connection
0x0004MCIF_CACHEDIf set, connection is currently in open cache
0x0008MCIF_ESMTPThis host speaks ESMTP
0x0010MCIF_EXPNEXPN command supported
0x0020MCIF_SIZESIZE option supported
0x0040MCIF_8BITMIMEBODY=8BITMIME supported
0x0080MCIF_7BITStrip this message to 7 bits
0x0100MCIF_MULTSTATMAIL11V3, handles MULT status
0x0200MCIF_INHEADERCurrently outputting header
0x0400MCIF_CVT8TO7Convert from 8 to 7 bits
0x0800MCIF_DSNDSN extension supported
0x1000MCIF_8BITOKOkay to send 8 bit characters
0x2000MCIF_CVT7TO8Convert from 7 to 8 bits
0x4000MCIF_INMIMECurrently reading MIME header

The stat is the exit status of the last delivered mail message to this connection. It is one of the values defined in <sysexits.h>. The err is the value of the last system error (if any), as defined in <errno.h>.

37.5.149 -d42.5

Trace caching and uncaching connections

The -d42.5 debugging switch shows connections being cached and freed:

mci_cache: caching addr (host) in slot slot
mci_uncache: uncaching addr (host) from slot slot (doquit)

Here, addr is the address in memory of the C language structure (struct mailer_con_info defined in sendmail.h) that defines the current (or about to be made) connection. The host is the name of the host to which the connection is to be made. The slot is an index into the array of structures that contain the connection information. For uncaching, the doquit is a Boolean that tells sendmail to close the connection if it is nonzero.

The -d91.100 debugging switch produces information identical to the above but logs its output at LOG_DEBUG instead of printing it:

qid: mci_cache: caching addr (host) in slot slot
qid: mci_uncache: uncaching addr (host) from slot slot (doquit)

Note that each line is prefixed by the queue identifier for the message (qid). The -d91.100 debugging switch is especially handy for monitoring caching when running sendmail as a daemon.

37.5.150 -d43.1

Trace MIME conversions

V8.7 sendmail can convert 8-bit MIME to 7 bits. The -d43.1 (a.k.a. -d43) debugging switch traces this process.

mime8to7: flags = mflags, boundaries =  boundaries printed here

Here, the internal mime8to7() routine has been called to do the conversion. The mflags are printed in hexadecimal, and are described in Table 37.18.

Table 37.18: Conversion Flags for mime8to7()
HexMnemonicDescription
0x00M87F_OUTERThis is the outer context
0x01M87F_NO8BITCan't have 8-bit in this section
0x02M87F_DIGESTCurrently processing a multipart digest

The boundaries is either <none> or a list of the boundaries found in the message. In multipart messages the -d43.1 debugging switch causes each boundary to be printed as it is found:

mime8to7: multi part boundary boundary printed here

37.5.151 -d43.3

See the final MIME boundary name

The -d43.3 debugging switch is used to see the final MIME boundary name that is selected:

mime8to7=>boundary (multipart)
mime8to7=>boundary (basic)

Each line is prefixed with three tabs.

The -d43.3 debugging switch is also used to trace 7- to 8-bit conversion. If a delivery agent has the F=9 flag set (see Section 30.8.6, F=9) and if the message has a Content-Transfer-Encoding: header that specifies Base64 or Quoted-Printable, sendmail will attempt to convert it from its encoded 7-bit form back into 8-bit form:

mime7to8 => base64 or quoted-printable  to 8bit done

37.5.152 -d43.5

Watch search for boundaries

The -d43.5 debugging switch allows you to watch the search for boundaries. First each line read is printed:

mimeboundary: line="line is printed here"...
                                                         -^
                                                      boundary, if found, printed here

Then, if the line contained a valid MIME boundary, the found boundary is printed at the end of the preceding.

37.5.153 -d43.8

Show the calculations

The sendmail program determines how to convert the MIME message by examining the first eighth of the file. If the first eighth of the total number of characters in the file have the high bit set, conversion will be with Base64; otherwise, it will be with Quoted-Printable (see Section 34.8.22, EightBitMode (8)). If the message is marked as binary, it is always converted with Base64. The -d43.8 debugging switch causes sendmail to print the result of this calculation:

mime8to7: hcount high bit(s) in bcount byte(s), cte=type

Here, cte= is either [none] or the content-transfer-encoding type, such as binary.

37.5.154 -d43.35

Show boundary lines as emitted

The -43.35 debugging switch causes each new boundary line to be printed as it is inserted into the message:

...-mid-boundary here
...-end boundary here-

The midboundary marks begin with a -. The ending-boundary mark begins and ends with a -.

37.5.155 -d43.36

Show content transfer encoding

The -43.36 debugging switch causes the encoding header to be printed as it is added to the message:

...Content-Transfer-Encoding:  type of encoding here

The type of encoding will either be the original as printed with cte= in -d43.8 above or Base64 or Quoted-Printable.

37.5.156 -d43.40

Show parse of Content-Type: header

The -43.40 debugging switch causes the contents of the parsed Content-Type: header to be displayed.

pvp[n] = "item"

For zero through n items that were parsed, each is printed on its own line.

37.5.157 -d43.99

Print the leading/following comments

The -d43.99 debugging switch tells sendmail to print each line of MIME commentary that precedes the leading boundary:

... leading commentary here
...-midboundary here

and the commentary that follows the last boundary:

...-end boundary here-
... trailing commentary here

37.5.158 -d43.100

Mark collect() and putheader()

The -d43.100 debugging switch causes sendmail to print a mark just after it has called collect() and after it has called putheader():

+++after collect
+++after putheader

The collect() routine is traced with the -d30 debugging switch, and putheader() is traced with the -d34 debugging switch.

37.5.159 -d44.4

Trace safefile()

The V8 sendmail program tries to be extra careful about file permissions, and the key to checking them is the internal safefile() function. The -d44.4 debugging switch [12] prints the parameters passed to the safefile() function:

[12] There is no -d44.1 debugging information.

safefile(fname, uid=uid, gid=gid, flags=sff_flags, mode=wantmode)

Here, the file named fname is being checked to determine whether the user identified by the uid, with the group gid, is allowed to find or use the file. The range of checking is determined by the hexadecimal sff_flags, described in Table 37.19. Where a file's permissions are required, the mode printed in wantmode will be used.

Table 37.19: safefile() Access Flags
FlagMnemonicDescription
0x000SFF_ANYFILENo special restrictions
0x001SFF_MUSTOWNUid must own this file
0x002SFF_NOSLINKFile must not be a symbolic link
0x004SFF_ROOTOKOkay for root to own this file
0x008SFF_RUNASREALUIDIf no controlling user, run as real uid
0x010SFF_NOPATHCHECKDon't bother checking leading path
0x020SFF_SETUIDOKSetuid files are okay
0x040SFF_CREATOkay to create the file if necessary
0x080SFF_REGONLYAllow regular files only
0x100SFF_OPENASROOTOpen as root instead of as uid

If the SFF_NOPATHCHECK flag is clear (0), sendmail examines each component of the path leading the file. If any component of the path is rejected, the -d44.4 debugging switch causes sendmail to print:

[dir fname]  reason for the rejection here

A path component can fail because stat(2) failed. If the uid is 0 for root, a warning is logged if a component is found to be group- or world-writable:

WARNING: writable directory fname

For each component in the path, safefile() checks to verify that this user has permission to search the directory. If the SFF_ROOTOK flag is not set (is clear), root (uid 0) access is special cased in that all directory components must be world-searchable.

Otherwise, the path component is accepted if it is owned by the uid and has the user search bit set or if its group is the same as gid and has the group search bit set. If NO_GROUP_SET is undefined when sendmail is compiled (see Section 18.8.31, NO-GROUP-SET) and the DontInitGroups option (see Section 34.8.19, DontInitGroups) is not set, each group to which uid belongs is also checked. Otherwise, the directory must be world-searchable.

If the fname could not be checked with stat(2), the -d44.4 debugging switch causes the reason to be printed:

 reason for failure here

If the file does not exist, it may need to be created. If so, sendmail checks to be sure that the uid has write permission. The result is printed with the -d44.4 debugging switch like this:

[final dir fname uid uid mode wantmode]  error here

If the file exists and if symbolic links are supported, the file is rejected if it is a symbolic link and if the SFF_NOSLINK flag is set. If the -d44.4 debugging switch is specified, this error is printed:

[slink mode mode]    EPERM

If the SFF_REGONLY flag is set the file must be a regular file. If it is not, it is rejected, and -d44.4 causes the following to be printed:

[non-reg mode mode]    EPERM

If wantmode has the write bits set, and the existing file has any execute bits set, the file is rejected and -d44.4 causes the following to be printed:

[exec bits mode]    EPERM

If the file has more than one link, the file is rejected and -d44.4 causes the following to be printed:

[link count nlinks]    EPERM

If the SFF_SETUIDOK flag is specified, if the file exists, if it has the suid bit set in the mode but no execute bits set in the mode, and if it is not owned by root, sendmail performs subsequent checks under the suid and sgid identities of the existing file. A similar process occurs with the sgid bit. Sendmail then prints:

[uid new_uid, stat filemode, mode wantmode]

If access is finally allowed, sendmail concludes the above with:

OK

Otherwise, it concludes with:

EACCES

37.5.160 -d44.5

Trace writable()

(useful)

The -d44.5 debugging switch displays the values passed to sendmail's internal writable() routine. This routine nearly duplicates the function of the access(3) call [13] but does it much more safely and allows checks to be made under the identity of the controlling user:

[13] It is more restrictive for root-owned files and can allow the suid semantics needed for delivery to files.

writable(fname, sff_flags)

Here, the fname is the full pathname of the file being checked. The sff_flags are documented in Table 37.19 above. Success or failure is described under -d44.4.

37.5.161 -d45.1

Show envelope sender

The -d45.1 (a.k.a. -d45) debugging switch causes sendmail to print the current form of the envelope sender address before it has fully rewritten that address into its final form:

setsender(addr)

If the addr is empty (as would be the case if the sender were being gathered from the header), sendmail prints NULL. The final envelope sender address is placed into the $f macro. (See Section 31.10.14, $f for a description of that macro and the process used by sendmail to set the sender's address.)

37.5.162 -d45.3

Show saved domain

If the F=C flag (see Section 30.8.15) is set for the delivery agent selected for the sender, sendmail will save the domain part of the address for later use. The -d45.3 causes the saved domain part to be printed:

Saving from domain: domain

The domain is saved in the e_fromdomain part of the C language structure that contains the envelope information for the sender. Later, if the F=C flag is set, this domain will be appended to any recipient addresses that lack a domain part.

37.5.163 -d45.5

Show don't send to sender

Unless a message is bounced, it will not be sent to the sender. The -d45.5 debugging switch causes sendmail to display sender information when this decision is made:

setsender: QDONTSEND  output of printaddr() here (see Section 37.3.1)

37.5.164 -d46.9

Show xf file's descriptors

The xf queue file (see Section 23.2.7, "The Transcript File: xf") contains a record of the errors and other information produced by a delivery agent. That information is used for bounced mail. The -d46.9 debugging switch [14] causes sendmail to dump the file descriptors for the opened xf file:

[14] There is no -d46.1 information.

openxscript(xfqid):
 output of dumpfd() here (see Section 37.5.13)

If sendmail cannot open an xf file, it logs this warning:

Can't create transcript file xfqid

It then tries to open /dev/null so that it can continue with the delivery. If that fails, it logs the following panic message and immediately exits:

Can't open /dev/null

Once the file is open (or not), sendmail turns it into an I/O stream with a call to fdopen(3). If that call fails, sendmail logs this message and immediately exits:

Can't create transcript stream xfqid

37.5.165 -d48.2

Trace calls to the check- rule sets

Beginning with V8.8, sendmail calls rule sets whose names begin with check_ (see Section 29.10, "The check_... Rule Sets") to filter incoming and outgoing mail. The -d48.2 debugging switch [15] can be used to display the workspace being passed to each such rule set:

[15] There is no -d48.1 information.

rscheck(name, left, right)

The name is the name of the named rule set being called. If right is missing, it prints as NULL, and the workspace passed to the rule set is:

left

If right is present, the workspace is:

left $| right

Here, the $| in the workspace is the $| operator.

37.5.166 -d49.1

Trace checkcompat()

The checkcompat() routine inside conf.c can be tuned to solve many problems (see Section 20.1, "How checkcompat() Works"). The default -d49.1 (a.k.a. 49) debugging switch inside it prints the arguments that were passed to it:

checkcompat(to=recipient, from=sender)

When designing your own checkcompat(), you should only use the -d49 category to trace it.

37.5.167 -d50.1

Show envelope being dropped

Deallocating an envelope frees that envelope's C language structure for future reuse. Deallocation also causes all the queued files for that mail message to be removed (except as possibly prevented by the -d51 debugging switch described in the next section). An envelope is deallocated after its mail message has been delivered to all recipients (including any failed deliveries).

The -d50.1 (a.k.a. -d50) debugging switch causes sendmail to print information about each envelope that is being deallocated:

dropenvelope loc id=ident flags=  output of printenvflags() here

This output shows the address in memory for the envelope's C language structure (loc), the queue identifier (ident, as used to name queued files), and the envelope flags as printed by printenvflags() (see Table 37.3 in Section 37.5.12).

Note that if the version of sendmail is pre-8.7, a Return-Receipt: header was in the message, and delivery was to at least one local recipient, the process of deallocation also causes acknowledgment of delivery to be returned to the sender and triggers error returns.

The -d50.1 debugging switch also shows the qf and df files just before they are removed:

===== Dropping [dq]fqid... queueit=bool, e_flags=  output of printenvflags() here

37.5.168 -d50.2

Show Booleans

The -d50.2 debugging switch shows the setting of three variables that determine how the envelope will be treated:

failure_return=val delay_return=val success_return=val queueit=val

A 1 indicates that the variable is true, a 0 indicates that it is false.

37.5.169 -d50.10

Also show the send queue

The -d50.10 debugging switch causes the current send queue to also be printed:

sendq= output of printaddr() here (see Section 37.3.1)

37.5.170 -d51.4

Show queue entries being unlocked

The -d51.4 [16] debugging switch causes V8 sendmail to print the following each time an envelope is unlocked in the queue:

[16] There is no -d51.1 information.

unlockqueue(qid)

Here, qid is the queue identifier.

37.5.171 -d51.104

Prevent unlink of xf file

The xf file (one of the files that form a queued mail message) holds error messages generated by a delivery agent. The last line of text in this file is made the value of the M line in the qf file (see Section 23.9.9, M line). Ordinarily, the xf file is removed after that error line is saved.

The -d51.104 debugging switch prevents sendmail from removing the xf file. If mail continually fails, this debugging switch can be used to save all error messages instead of just the one that is usually saved in the qf file.

37.5.172 -d52.1

Show disconnect from controlling TTY

When sendmail runs as a daemon, it must disconnect itself from the terminal device that is used to run it. This prevents keyboard signals from killing it and prevents it from hanging (on a dial-in line waiting for carrier detect, for example).

The -d52.1 (a.k.a. -d52) debugging switch shows sendmail disconnecting from the controlling terminal device:

disconnect: In fd Out fd, e=addr

For both its input and output connections, the fd is a decimal representation of the file descriptor number. The addr is a hexadecimal representation of the address that contains the envelope information. If the L logging level option is greater than 71, sendmail syslog(3)'s the following message to show that it has disconnected:

in background, pid=pid

Here, pid is the process identification number of the child process (the daemon).

37.5.173 -d52.100

Prevent disconnect from controlling tty

(useful)

The -d52.100 debugging switch [17] prevents sendmail from disconnecting from its controlling terminal device. To show that it is skipping the disconnect, it prints:

[17] This was formerly the -d52.5 debugging switch.

don't

This debugging switch is useful for debugging the daemon. Note that this -d52.100 prevents the detach but allows the daemon to fork(2). This differs from the behavior of the -d99.100 debugging switch.

37.5.174 -d53.99

Trace xclose()

Ordinarily, files are closed silently. The -d53.99 [18] debugging switch can be used to observe file closings. Just before the file is closed, sendmail prints:

[18] There is no -d53.1 information.

xfclose(fp) what file

Here, fp is the file pointer for the open file, printed in hexadecimal. The what is an indication of the internal function that requires the close (such as savemail or mci_uncache). The file is the name of the file to be closed.

If the close fails, the following is also printed:

xfclose FAILURE: why

Here, why is the text corresponding to the error value returned by fclose(3) (see sys_errlist(3)).

37.5.175 -d54.1

Show error return and output message

The exit values that are returned by sendmail are documented in Section 36.5. The -d54.1 debugging switch shows the exit value being set by the internal syserr() routine:

syserr: ExitStat = num

Here, num corresponds to the values defined in <sysexits.h>.

37.5.176 -d54.8

Show message and flags

The -d54.8 debugging switch causes the text of the error message to be printed along with the flags that control its actual output:

-- message (hold) (held)

If (hold) appears, it means that the message will be held (stored) and not output. If (held) appears, it means that the message was previously held and should not be added to the xf file. If neither is printed, the message will be logged and appended to the xf file. If the message on output fails, sendmail will attempt to log this panic message:

qid: SYSERR: putoutmsg (host): error on output channel sending "message": err

If the message was never queued, the qid will print as NOQUEUE. If you are not currently connected to a host, it will print as NO-HOST. The err is the error that caused the message to fail (as defined in either <sys/errno.h> or sysexits.h).

37.5.177 -d55.60

Show file locking

The sendmail program tries to lock every file before reading or writing it. If sendmail was compiled with HASFLOCK defined (see Section 18.8.9, HAS...), it uses flock(3) to lock and unlock files. If HASFLOCK is not defined, sendmail tries to lock and unlock with fcntl(2).

The -d55.60 [19] debugging switch tells sendmail to print how it is about to try to lock a file:

[19] There is no -d55.1 information.

lockfile(filename, action=set, type=l_type)
lockfile(filename, type=what)

The first form is printed if HASFLOCK is not defined. In it, sendmail is about to use fcntl(2) to lock the file. The action is a decimal representation of the F_SET flag that is fcntl(2)'s second argument. The l_type is the l_type structure member of fcntl(2)'s third argument (see the online manual for fcntl(2)).

The second form is printed if HASFLOCK is defined so that flock(2) will be used. In it, what is the type of locking to be performed, printed in octal, as described in Table 37.20.

Table 37.20: Flags That Control File Locking
FlagMnemonicDescription
001LOCK_SHMake it a shared lock
002LOCK_EXMake it an exclusive lock
004LOCK_NBMake it a nonblocking lock
010LOCK_UNUnlock the file

For both forms of locking, if the file is successfully locked, the above debugging output is concluded with:

SUCCESS

Otherwise, it is concluded with:

(error message here) FAILURE

In this later instance, regardless of the setting of this debugging flag, sendmail will also log the following error message:

cannot lock(filename, fd=num, type=what, omode=octal, euid=euid)

Here, lock is either lockf or flock. The filename and fd are the file name and file descriptor for the file. The what is the same as described in Table 37.20. If F_GETFL was defined at the system level when sendmail was compiled, then omode is an octal representation of the value returned by an fcntl(2) F_GETFL call; otherwise, it is a -1 in octal. The euid is the effective uid under which sendmail was running at the time.

37.5.178 -d56.1

Persistent host status tracing

The -d56.1 (a.k.a. -d56) debugging switch tells sendmail to print a record of each step it is going through when saving and updating its persistent host status. The HostStatusDirectory option (see Section 34.8.31, HostStatusDirectory) specifies where and whether persistent host status will be saved. Just before a status file is updated, and if the SingleThreadDelivery option (see Section 34.8.64, SingleThreadDelivery) is true, it needs to be locked:

mci_lock_host: attempting to lock host

Here, host is the name of the host whose status is being saved or updated. If the hostname is empty (as in the case of an address that contains only an RFC822 comment), one of the following errors is printed for an attempt to lock or unlock the host information:

mci_lock_host: NULL mci
mci_unlock_host: NULL mci

After the status file is locked, sendmail will transfer the information from that file into its internal mci structure:

mci_load_persistent: Attempting to load persistent information for host

Again, if the hostname is empty, this error will print:

mci_load_persistent: NULL

If sendmail was unable to translate the hostname into a UNIX path, the -d56.1 debugging switch causes it to print:

mci_load_persistent: Couldn't generate host path

If sendmail was unable open the host status file, it prints:

mci_load_persistent: open(filename): host

Similarly, when sendmail needs to store or update the host information, it first prints that it is doing so:

mci_store_persistent: Storing information for host

If sendmail could not open the host status file, it prints:

mci_store_persistent: no statfile

The internals of the status file are described in Appendix Appendix B, Host Status File Internals.

Ordinarily, sendmail is silent about its inability to open status files when printing its host information with the hoststat(1) command (see Section 36.1.1, "hoststat (V8.8 and Above)"). But if the -d56.1 debugging switch is used, sendmail will complain:

mci_print_persistent: cannot open filename: host

When its host information is being purged with the purgestat(1) command (see Section 36.1.4, "purgestat (V8.8 and Above)"), the -d56.1 debugging switch tells sendmail to show what it is trying to achieve:

mci_purge_persistent: purging path
mci_purge_persistent: dpurge directory

37.5.179 -d56.2

More persistent host status tracing

The -d56.2 debugging switch causes sendmail to show additional information about what it is trying to do. Just before attempting to lock a status file, it prints:

mci_lock_host: attempting to lock host

If a path could not be generated from the hostname, sendmail prints this error:

mci_lock_host: Failed to generate host path for host

If sendmail could not lock the status file, it prints:

mci_lock_host: couldn't get lock on filename

When sendmail is about to update a status file, just before unlocking that file, it announces that fact:

mci_unlock_host: store prior to unlock

The process of updating or reading a status file begins by sendmail traversing the directory hierarchy under which that file is stored. If sendmail is unable to stat(2) any component of that path, it prints the following error:

mci_traverse: Failed to stat component: reason for failure

If sendmail cannot descend into the next directory, it prints:

mci_traverse: opendir component: reason for failure

When purging its host information with the purgestat(1) command (see Section 36.1.4), if sendmail cannot remove the status file, it prints:

mci_purge_persistent: failed to unlink filename: reason for failure

And if it cannot remove any of the directory components, it prints:

mci_purge_persistent: rmdir directory: reason for failure

37.5.180 -d56.12

Perform a sanity check

As a "sanity check," the -d56.12 debugging switch causes sendmail to print the following if the lock was successfully acquired on the status file:

mci_lock_host: Sanity check - lock is good

37.5.181 -d56.80

Trace creating the path to the status file

If the status file does not exist, sendmail recursively makes the directories leading to it. The -d56.80 debugging switch is used to trace this process:

mci_generate_persistent_path(host): FAILURE errno
mci_generate_persistent_path(host): SUCCESS path

If this process of making directories fails, errno is printed, as listed in <errno.h>. If it succeeds, the path created is displayed.

37.5.182 -d56.93

Dump MCI record for the host

The -d56.93 debugging switch causes sendmail to dump the connection cache information associated with a host's status file:

mci_read_persistent: fp=hex, mci= output of mci_dump() here (see Section 37.5.44)

Here, hex is the file pointer of the open status file printed in hexadecimal. That is followed by a dump of the MCI record for the host.

37.5.183 -d57.2

Monitor vsnprintf() overflows

If HASSNPRINTF is not defined, sendmail emulates the snprintf(3) function. If the internal buffer of that emulation overflows, the -d57.2 debugging switch causes this warning to be printed:

vsnprintf overflow: first 200 characters of buffer

Note that you may have to also use the -v command-line switch to make this output visible.

37.5.184 -d59

XLA from contrib

(obsolete)

See the XLA package in the contrib/xla directory as distributed with the V8 sendmail source. Note that XLA is no longer distributed with sendmail as of V8.8.

37.5.185 -d60.1

Trace map lookups inside rewrite()

(useful)

Rules defined by the R configuration command are rewritten by sendmail's internal rewrite() subroutine. The $[ and $( lookup operators (see Section 33.4.3, "$[ and $]: A Special Case" and Section 33.4, "Use Maps with $( and $) in Rules") cause sendmail to look up keys in databases (maps).

If sendmail is running in deferred mode (see Section 34.8.16), it skips map lookups because they may cause DNS accesses. The -d60.1 (a.k.a. -d60) debugging switch causes sendmail to print that it is skipping the lookup:

map_lookup(name, key) => DEFERRED

Here, name is the map type, such as dequote or host. The key is the information being looked up.

If running in something other than deferred mode, sendmail performs the lookup. If the lookup fails (if key is not found), sendmail prints:

map_lookup(name, key) => NOT FOUND (stat)

Here, stat is the number of the error that caused the failure. If it is 0, then the lookup failed merely because the key was not found. Otherwise, it corresponds to the error numbers in <sysexits.h>. Then if stat is the special value 75 (for EX_TEMPFAIL), sendmail also prints:

map_lookup(name, key) tempfail: errno=err

Here, err is the error number that corresponds to the errors listed in <errno.h>.

If the key is successfully found, sendmail prints:

map_lookup(name, key) => replacement value here (stat)

Note that the replacement value will be whatever value was defined by the -a database switch when the K command defined the map (see Section 33.3.4.2, "-a append tag on successful match (V8.1 and above)").

37.5.186 -d61.10

Trace gethostbyname()

The gethostbyname(3) library routine is called by sendmail every time sendmail needs to find the canonical name of a host. The -d61.10 [20] debugging switch shows the result of that lookup:

[20] There is no -d61.1 information.

_switch_gethostbyname_r(host)... canonical name here
__switch_gethostbyname(host)... canonical name here
gethostbyname(host)... canonical name here

In all three lines of output, the host was looked up to find its canonical name. If one was found, its canonical name is printed; otherwise, failure is printed. The first two lines show variations on gethostbyname(3) that was required by some early SysVR4-based machines. These represent sendmail's attempt to canonify the host no matter what.

37.5.187 -d62.1

Log file descriptors before and after all deliveries

The -d62.1 (a.k.a. -d62) debugging switch causes sendmail to log the state of all of its file descriptors. It does this once just before it starts to process the list of its recipients and again just after it has completed delivery of all its recipients. Note that this debugging switch is unusual in that it causes its output to be logged with syslog(3), rather than written to stdout.

37.5.188 -d62.8

Log file descriptors before each delivery

The -d62.8 debugging switch causes sendmail to log the state of all its file descriptors just before undertaking delivery of each message.

37.5.189 -d62.10

Log file descriptors after each delivery

The -d62.10 debugging switch causes sendmail to log the state of all its file descriptors just after completing delivery of each message.

37.5.190 -d80.1

Content-Length: header (Sun enhancement)

The -d80.1 (a.k.a. -d80) debugging switch is used to watch how Sun's version of sendmail handles the Content-Length: header. As soon as the size of the body of a message is known, Sun's sendmail stores it in the envelope information. When the time comes to emit the Content-Length: header, that information is fetched. If the size is unknown, the -d80.1 debugging switch causes sendmail to print:

content_length(): Error:  Message bodysize undefined !

If the size is known, it is reduced by the number and size of the end-of-line characters (as defined by the delivery agent's E = equate). If the delivery agent's F=E flag is set (see Section 30.8.19, F=E), the size is further reduced by the number of five character "From " strings that begin lines in the message body. The -d80 debugging switch then causes the final result to be printed:

Content length =  final length here

37.5.191 -d81.1

> option for remote mode (Sun enhancement)

In V8.1 sendmail the letter R was co-opted by the Berkeley distribution as an option name. This forced Sun to change the name of its former R option into the new > option. The -d81.1 (a.k.a. -d80) debugging switch causes Sun's sendmail to display the status of this remote mode:

verify_mail_server(): remote mode is  either on or off
mail server =  host name here

If the > option is declared, on is printed, and the name of the remote mail host is displayed, if known. See Section 38.18, "The > Option" for a further description of this option.

37.5.192 -d91.100

Log caching and uncaching connections

The -d91.100 debugging switch [21] causes the same information to be logged with syslog(3) as is printed by the -d42.5 debugging switch.

[21] There is no -d91.1 information available.

37.5.193 -d99.100

Prevent backgrounding the daemon

(useful)

The -d99.100 debugging switch [22] prevents the sendmail daemon from forking and putting itself into the background. This leaves the running daemon connected to your terminal so that you can see other debugging output. For example,

[22] There is no -d99.1 information available.

# /usr/lib/sendmail -bd -d99.100 -d9.30

This allows you to watch the daemon perform RFC1413 identification queries when SMTP connections are made. See also -d52.100, which prevents sendmail from disconnecting from its controlling terminal device, or the -bD command-line switch (Section 36.7.4, -bD), which does both.


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