Полезная информация




VIRTUAL(5)                                             VIRTUAL(5)


NAME
       virtual - format of Postfix virtual table

SYNOPSIS
       postmap /etc/postfix/virtual

DESCRIPTION
       The  optional  virtual  table  specifies  redirections for
       local and non-local recipients or  domains.  The  redirec-
       tions  are used by the cleanup(8) daemon. The redirections
       are recursive.

       The virtual redirection is applied only to  the  recipient
       envelope  address,  and  does  not affect message headers.
       Think Sendmail rule set S0, if you like. Use  canonical(5)
       mapping  to  rewrite header and envelope addresses in gen-
       eral.

       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/virtual in order to rebuild
       the indexed file after changing the virtual 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.

TABLE FORMAT
       Typical  support  for a virtual domain looks like the fol-
       lowing:

           virtual.domain       anything (right-hand content does not matter)
           postmaster@virtual.domain    postmaster
           user1@virtual.domain address1
           user2@virtual.domain address2, address3

       With this, the SMTP server accepts mail for virtual.domain
       and  rejects mail for unknown@virtual.domain as undeliver-
       able.

       The format of the virtual table is  as  follows,  mappings
       being tried in the order as listed in this manual page:

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





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VIRTUAL(5)                                             VIRTUAL(5)


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

       user@domain address, address, ...
              Mail  for  user@domain  is  redirected  to address.
              This form has the highest precedence.

       user address, address, ...
              Mail for user@site is redirected  to  address  when
              site  is equal to $myorigin, when site is listed in
              $mydestination,   or   when   it   is   listed   in
              $inet_interfaces.

              This  functionality  overlaps with functionality of
              the local alias(5) database. The difference is that
              virtual   mapping   can  be  applied  to  non-local
              addresses.

       @domain address, address, ...
              Mail for  any  user  in  domain  is  redirected  to
              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.   This
       works for the first address in the expansion only.

ADDRESS EXTENSION
       When  the search fails, and the address localpart contains
       the optional recipient delimiter (e.g.,  user+foo@domain),
       the  search  is  repeated for the unextended address (e.g.
       user@domain), and the unmatched address extension is prop-
       agated  to the result of expansion. 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.



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VIRTUAL(5)                                             VIRTUAL(5)


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

       virtual_maps
              List of virtual mapping tables.

       Other parameters of interest:

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

       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
       pcre_table(5) format of PCRE tables
       regexp_table(5) format of POSIX regular expression tables

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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