Полезная информация




CANONICAL(5)                                         CANONICAL(5)


NAME
       canonical - format of Postfix canonical table

SYNOPSIS
       postmap /etc/postfix/canonical

DESCRIPTION
       The  optional  canonical file specifies an address mapping
       for local and non-local addresses. The mapping is used  by
       the  cleanup(8) daemon.  The address mapping is recursive.

       Normally, the file serves as input to the postmap(1)  com-
       mand.  The result, an indexed file in dbm or db format, is
       used for fast searching by the mail  system.  Execute  the
       command postmap /etc/postfix/canonical in order to rebuild
       the indexed file after changing the canonical table.

       When the table is provided via other means  such  as  NIS,
       LDAP  or  SQL,  the  same lookups are done as for ordinary
       indexed files.

       Alternatively, the table can be  provided  as  a  regular-
       expression map where patterns are given as regular expres-
       sions. In that case, the lookups are done  in  a  slightly
       different way as described below.

       The   canonical   mapping   affects  both  message  header
       addresses (i.e. addresses that appear inside messages) and
       message  envelope  addresses  (for  example, the addresses
       that are used in SMTP protocol commands).  Think  Sendmail
       rule set S3, if you like.

       Typically,  one  would  use the canonical table to replace
       login  names  by  Firstname.Lastname,  or  to   clean   up
       addresses produced by legacy mail systems.

       The  canonical  mapping is not to be confused with virtual
       domain support. Use the virtual(5) map for that purpose.

       The canonical mapping is not to  be  confused  with  local
       aliasing.  Use the aliases(5) map for that purpose.

TABLE FORMAT
       The format of the canonical table is as follows:

       blanks and comments
              Blank  lines  are  ignored,  as are lines beginning
              with `#'.

       pattern result
              When pattern matches a mail address, replace it  by
              the corresponding result.

       With lookups from indexed files such as DB or DBM, or from



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CANONICAL(5)                                         CANONICAL(5)


       networked tables such as NIS, LDAP or  SQL,  patterns  are
       tried in the order as listed below:

       user@domain address
              user@domain  is  replaced by address. This form has
              the highest precedence.

              This form useful to clean up addresses produced  by
              legacy  mail  systems.  It can also be used to pro-
              duce Firstname.Lastname style  addresses,  but  see
              below for a simpler solution.

       user address
              user@site is replaced by address when site is equal
              to $myorigin, when site is  listed  in  $mydestina-
              tion, or when it is listed in $inet_interfaces.

              This  form  is  useful for replacing login names by
              Firstname.Lastname.

       @domain address
              Every address in domain  is  replaced  by  address.
              This form has the lowest precedence.

       In  all the above forms, when address has the form @other-
       domain, the result is the same user in otherdomain.

ADDRESS EXTENSION
       When table lookup fails, and the  address  localpart  con-
       tains    the    optional    recipient   delimiter   (e.g.,
       user+foo@domain), the search is  repeated  for  the  unex-
       tended  address  (e.g.   user@domain),  and  the unmatched
       extension is propagated to the result of table lookup. The
       matching order is: user+foo@domain, user@domain, user+foo,
       user, and @domain.

REGULAR EXPRESSION TABLES
       This section describes how the table lookups  change  when
       the table is given in the form of regular expressions. For
       a description of regular expression lookup  table  syntax,
       see regexp_table(5) or pcre_table(5).

       Each  pattern  is  a regular expression that is applied to
       the entire address being looked up. Thus, user@domain mail
       addresses  are  not  broken up into their user and @domain
       constituent parts, nor is user+foo broken up into user and
       foo.

       Patterns  are  applied  in  the  order as specified in the
       table, until a pattern is found that  matches  the  search
       string.

       Results  are the same as with normal indexed file lookups,
       with the additional feature that parenthesized  substrings



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CANONICAL(5)                                         CANONICAL(5)


       from  the pattern can be interpolated as $1, $2 and so on.

BUGS
       The table format does not understand quoting  conventions.

CONFIGURATION PARAMETERS
       The  following  main.cf parameters are especially relevant
       to this topic. See the Postfix  main.cf  file  for  syntax
       details  and  for  default  values. Use the postfix reload
       command after a configuration change.

       canonical_maps
              List of canonical mapping tables.

       recipient_canonical_maps
              Address  mapping  lookup  table  for  envelope  and
              header recipient addresses.

       sender_canonical_maps
              Address  mapping  lookup  table  for  envelope  and
              header sender addresses.

       Other parameters of interest:

       inet_interfaces
              The network interface addresses  that  this  system
              receives mail on.

       masquerade_domains
              List  of  domains  that hide their subdomain struc-
              ture.

       masquerade_exceptions
              List of user names that are not subject to  address
              masquerading.

       mydestination
              List  of  domains  that  this mail system considers
              local.

       myorigin
              The domain that is appended to locally-posted mail.

       owner_request_special
              Give special treatment to owner-xxx and xxx-request
              addresses.

SEE ALSO
       cleanup(8) canonicalize and enqueue mail
       postmap(1) create mapping table
       virtual(5) virtual domain mapping
       pcre_table(5) format of PCRE tables
       regexp_table(5) format of POSIX regular expression tables




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CANONICAL(5)                                         CANONICAL(5)


LICENSE
       The Secure Mailer license must be  distributed  with  this
       software.

AUTHOR(S)
       Wietse Venema
       IBM T.J. Watson Research
       P.O. Box 704
       Yorktown Heights, NY 10598, USA
















































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