canonical - Postfix canonical table format


   postmap /etc/postfix/canonical

   postmap -q "string" /etc/postfix/canonical

   postmap -q - /etc/postfix/canonical <inputfile


   The  optional canonical(5) table specifies an address mapping for local
   and non-local addresses. The mapping is used by the cleanup(8)  daemon,
   before  mail  is  stored  into  the  queue.   The  address  mapping  is

   Normally, the canonical(5) table is  specified  as  a  text  file  that
   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.
   Execute  the  command  "postmap  /etc/postfix/canonical"  to rebuild an
   indexed file after changing the corresponding text file.

   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  expressions,  or  lookups  can  be
   directed to TCP-based server. In those cases, the lookups are done in a
   slightly different way as described  below  under  "REGULAR  EXPRESSION

   By  default  the  canonical(5)  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).  This  is  controlled  with  the  canonical_classes

   NOTE:  Postfix  versions  2.2  and  later  rewrite message headers from
   remote   SMTP   clients   only    if    the    client    matches    the
   local_header_rewrite_clients       parameter,       or      if      the
   remote_header_rewrite_domain  configuration   parameter   specifies   a
   non-empty  value.  To  get  the  behavior  before  Postfix 2.2, specify
   "local_header_rewrite_clients = static:all".

   Typically, one would use the canonical(5) table to replace login  names
   by Firstname.Lastname, or to clean up addresses produced by legacy mail

   The canonical(5) mapping is not  to  be  confused  with  virtual  alias
   support  or  with local aliasing. To change the destination but not the
   headers, use the virtual(5) or aliases(5) map instead.


   The search string is folded to lowercase before database lookup. As  of
   Postfix  2.3,  the search string is not case folded with database types
   such as regexp: or pcre: whose lookup fields can match both  upper  and
   lower case.


   The input format for the postmap(1) command is as follows:

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

   blank lines and comments
          Empty lines and whitespace-only lines are ignored, as are  lines
          whose first non-whitespace character is a `#'.

   multi-line text
          A  logical  line  starts  with  non-whitespace text. A line that
          starts with whitespace continues a logical line.


   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
          Replace user@domain  by  address.  This  form  has  the  highest

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

   user address
          Replace  user@site  by  address when site is equal to $myorigin,
          when site is listed in $mydestination, or when it is  listed  in
          $inet_interfaces or $proxy_interfaces.

          This   form   is   useful   for   replacing   login   names   by

   @domain address
          Replace other addresses in domain by address.  This form has the
          lowest precedence.

          Note:  @domain  is  a  wild-card.  When  this form is applied to
          recipient addresses, the Postfix SMTP server  accepts  mail  for
          any  recipient  in  domain, regardless of whether that recipient
          exists.  This may turn  your  mail  system  into  a  backscatter
          source:  Postfix  first accepts mail for non-existent recipients
          and then tries to return that mail  as  "undeliverable"  to  the
          often forged sender address.


   The lookup result is subject to address rewriting:

   *      When  the  result  has the form @otherdomain, the result becomes
          the same user in otherdomain.

   *      When "append_at_myorigin=yes", append "@$myorigin" to  addresses
          without "@domain".

   *      When "append_dot_mydomain=yes", append ".$mydomain" to addresses
          without ".domain".


   When a mail address localpart contains the optional recipient delimiter
   (e.g.,  user+foo@domain),  the  lookup  order becomes: user+foo@domain,
   user@domain, user+foo, user, and @domain.

   The  propagate_unmatched_extensions  parameter  controls   whether   an
   unmatched address extension (+foo) is propagated to the result of table


   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 indexed file lookups, with the  additional
   feature   that   parenthesized  substrings  from  the  pattern  can  be
   interpolated as $1, $2 and so on.


   This section describes how the table lookups change  when  lookups  are
   directed   to  a  TCP-based  server.  For  a  description  of  the  TCP
   client/server lookup protocol, see tcp_table(5).  This feature  is  not
   available up to and including Postfix version 2.4.

   Each  lookup operation uses the entire address once.  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.

   Results are the same as with indexed file lookups.


   The table format does not understand quoting conventions.


   The  following  parameters  are especially relevant.  The text
   below provides only a  parameter  summary.  See  postconf(5)  for  more
   details including examples.

          What addresses are subject to canonical address mapping.

          List of canonical mapping tables.

          Address  mapping  lookup table for envelope and header recipient

          Address mapping lookup table  for  envelope  and  header  sender

          A  list  of  address  rewriting  or  forwarding  mechanisms that
          propagate an address extension from the original address to  the
          result.   Specify  zero  or  more  of canonical, virtual, alias,
          forward, include, or generic.

   Other parameters of interest:

          The network interface addresses that this system  receives  mail
          on.   You  need  to  stop  and start Postfix when this parameter

          Rewrite message header addresses in mail from these clients  and
          update incomplete addresses with the domain name in $myorigin or
          $mydomain; either  don't  rewrite  message  headers  from  other
          clients at all, or rewrite message headers and update incomplete
          addresses    with    the     domain     specified     in     the
          remote_header_rewrite_domain parameter.

          Other  interfaces that this machine receives mail on by way of a
          proxy agent or network address translator.

          List of address classes subject to masquerading: zero or more of
          envelope_sender,        envelope_recipient,       header_sender,

          List of domains that hide their subdomain structure.

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

          List of domains that this mail system considers local.

          The domain that is appended to locally-posted mail.

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

          Don't rewrite message headers from remote clients  at  all  when
          this  parameter is empty; otherwise, rewrite message headers and
          append the specified domain name to incomplete addresses.


   cleanup(8), canonicalize and enqueue mail
   postmap(1), Postfix lookup table manager
   postconf(5), configuration parameters
   virtual(5), virtual aliasing


   Use "postconf readme_directory" or "postconf html_directory" to  locate
   this information.
   DATABASE_README, Postfix lookup table overview
   ADDRESS_REWRITING_README, address rewriting guide


   The Secure Mailer license must be distributed with this software.


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

   Wietse Venema
   Google, Inc.
   111 8th Avenue
   New York, NY 10011, USA



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