CANONICAL(5)                                         CANONICAL(5)

       canonical - format of Postfix canonical table

       postmap /etc/postfix/canonical

       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.

       The file serves as input to the  postmap(1)  command.  The
       result,  an  indexed file in dbm or db format, is used for
       fast searching by the mail system. After an update it  may
       take  a  minute  or  so before the change becomes visible.
       Issue a postfix reload command to eliminate the delay.

       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.

       The format of the canonical 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 `#'.

       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.


CANONICAL(5)                                         CANONICAL(5)

              This form is useful for replacing  login  names  by

       @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.

       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  table format does not understand quoting conventions.

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

              List of canonical mapping tables.

              Address  mapping  lookup  table  for  envelope  and
              header recipient addresses.

              Address  mapping  lookup  table  for  envelope  and
              header sender addresses.

       Other parameters of interest:

              The  network  interface  addresses that this system
              receives mail on.

              List of domains that hide  their  subdomain  struc-

              List  of  domains  that  this mail system considers

              The domain that is appended to locally-posted mail.


CANONICAL(5)                                         CANONICAL(5)

       cleanup(8) canonicalize and enqueue mail
       postmap(1) create mapping table
       virtual(5) virtual domain mapping

       See  the  Postfix  LICENSE, which must be distributed with
       this software.

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