Provided by: postfix_2.2.10-1_i386 bug

NAME

       canonical - Postfix canonical table format

SYNOPSIS

       postmap /etc/postfix/canonical

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

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

DESCRIPTION

       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
       recursive.

       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"  in  order  to
       rebuild the indexed file after changing the 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 that case, the lookups are done in a
       slightly different way as described  below  under  "REGULAR  EXPRESSION
       TABLES" and "TCP-BASED TABLES".

       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). Think Sendmail rule set S3, if you like.   This  is
       controlled with the canonical_classes parameter.

       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
       systems.

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

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

TABLE FORMAT

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

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

       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.

TABLE SEARCH ORDER

       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
              precedence.

              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
              Firstname.Lastname.

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

RESULT ADDRESS REWRITING

       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".

ADDRESS EXTENSION

       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
       lookup.

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

TCP-BASED TABLES

       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 2.2.

       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.

BUGS

       The table format does not understand quoting conventions.

CONFIGURATION PARAMETERS

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

       canonical_classes
              What addresses are subject to canonical address mapping.

       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.

       propagate_unmatched_extensions
              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:

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

       local_header_rewrite_clients
              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.

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

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

       masquerade_domains
              List of domains that hide their subdomain structure.

       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.

       remote_header_rewrite_domain
              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.

SEE ALSO

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

README FILES

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

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

                                                                  CANONICAL(5)