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<!doctype html public "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html> <head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<title> Postfix manual - canonical(5) </title>
</head> <body> <pre>
CANONICAL(5)                                                      CANONICAL(5)

<b>NAME</b>
       canonical - Postfix canonical table format

<b>SYNOPSIS</b>
       <b>postmap /etc/postfix/canonical</b>

       <b>postmap -q "</b><i>string</i><b>" /etc/postfix/canonical</b>

       <b>postmap -q - /etc/postfix/canonical</b> &lt;<i>inputfile</i>

<b>DESCRIPTION</b>
       The  optional <a href="canonical.5.html"><b>canonical</b>(5)</a> table specifies an address mapping for local
       and non-local addresses. The mapping is used by the <a href="cleanup.8.html"><b>cleanup</b>(8)</a>  daemon,
       before  mail  is  stored into the queue.  The address mapping is recur-
       sive.

       Normally, the <a href="canonical.5.html"><b>canonical</b>(5)</a> table is  specified  as  a  text  file  that
       serves as input to the <a href="postmap.1.html"><b>postmap</b>(1)</a> command.  The result, an indexed file
       in <b>dbm</b> or <b>db</b> format, is used for fast searching  by  the  mail  system.
       Execute  the  command  "<b>postmap  /etc/postfix/canonical</b>"  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
       TABLES" or "TCP-BASED TABLES".

       By  default  the  <a href="canonical.5.html"><b>canonical</b>(5)</a>  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  <b><a href="postconf.5.html#canonical_classes">canonical_classes</a></b>
       parameter.

       NOTE:  Postfix  versions  2.2  and  later  rewrite message headers from
       remote SMTP clients only if the  client  matches  the  <a href="postconf.5.html#local_header_rewrite_clients">local_header_re</a>-
       <a href="postconf.5.html#local_header_rewrite_clients">write_clients</a> parameter, or if the <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> config-
       uration parameter specifies a non-empty  value.  To  get  the  behavior
       before    Postfix    2.2,   specify   "<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>   =
       <a href="DATABASE_README.html#types">static</a>:all".

       Typically, one would use the <a href="canonical.5.html"><b>canonical</b>(5)</a> table to replace login  names
       by <i>Firstname.Lastname</i>, or to clean up addresses produced by legacy mail
       systems.

       The <a href="canonical.5.html"><b>canonical</b>(5)</a> mapping is not to be confused with <i>virtual alias</i>  sup-
       port  or  with  local  aliasing.  To change the destination but not the
       headers, use the <a href="virtual.5.html"><b>virtual</b>(5)</a> or <a href="aliases.5.html"><b>aliases</b>(5)</a> map instead.

<b>CASE FOLDING</b>
       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 <a href="regexp_table.5.html">regexp</a>: or <a href="pcre_table.5.html">pcre</a>: whose lookup fields can match both  upper  and
       lower case.

<b>TABLE FORMAT</b>
       The input format for the <a href="postmap.1.html"><b>postmap</b>(1)</a> command is as follows:

       <i>pattern address</i>
              When  <i>pattern</i>  matches  a mail address, replace it by the corre-
              sponding <i>address</i>.

       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.

<b>TABLE SEARCH ORDER</b>
       With lookups from indexed files such as DB or DBM,  or  from  networked
       tables  such  as  NIS,  LDAP  or SQL, each <i>user</i>@<i>domain</i> query produces a
       sequence of query patterns as described below.

       Each query pattern is sent to each specified lookup table before trying
       the next query pattern, until a match is found.

       <i>user</i>@<i>domain address</i>
              Replace <i>user</i>@<i>domain</i> by <i>address</i>. This form has the highest prece-
              dence.

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

       <i>user address</i>
              Replace <i>user</i>@<i>site</i> by <i>address</i> when <i>site</i> is  equal  to  $<b><a href="postconf.5.html#myorigin">myorigin</a></b>,
              when  <i>site</i>  is listed in $<b><a href="postconf.5.html#mydestination">mydestination</a></b>, or when it is listed in
              $<b><a href="postconf.5.html#inet_interfaces">inet_interfaces</a></b> or $<b><a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a></b>.

              This form is useful for replacing login names by <i>Firstname.Last-</i>
              <i>name</i>.

       @<i>domain address</i>
              Replace other addresses in <i>domain</i> by <i>address</i>.  This form has the
              lowest precedence.

              Note: @<i>domain</i> is a wild-card.  When  this  form  is  applied  to
              recipient  addresses,  the  Postfix SMTP server accepts mail for
              any recipient in <i>domain</i>, 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.

<b>RESULT ADDRESS REWRITING</b>
       The lookup result is subject to address rewriting:

       <b>o</b>      When the result has the form @<i>otherdomain</i>,  the  result  becomes
              the same <i>user</i> in <i>otherdomain</i>.

       <b>o</b>      When  "<b><a href="postconf.5.html#append_at_myorigin">append_at_myorigin</a>=yes</b>", append "<b>@$<a href="postconf.5.html#myorigin">myorigin</a></b>" to addresses
              without "@domain".

       <b>o</b>      When "<b><a href="postconf.5.html#append_dot_mydomain">append_dot_mydomain</a>=yes</b>", append "<b>.$<a href="postconf.5.html#mydomain">mydomain</a></b>" to addresses
              without ".domain".

<b>ADDRESS EXTENSION</b>
       When a mail address localpart contains the optional recipient delimiter
       (e.g., <i>user+foo</i>@<i>domain</i>), the  lookup  order  becomes:  <i>user+foo</i>@<i>domain</i>,
       <i>user</i>@<i>domain</i>, <i>user+foo</i>, <i>user</i>, and @<i>domain</i>.

       The   <b><a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a></b>   parameter  controls  whether  an
       unmatched address extension (<i>+foo</i>) is propagated to the result of table
       lookup.

<b>REGULAR EXPRESSION TABLES</b>
       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 <a href="regexp_table.5.html"><b>regexp_table</b>(5)</a> or <a href="pcre_table.5.html"><b>pcre_table</b>(5)</a>.

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

       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  interpo-
       lated as <b>$1</b>, <b>$2</b> and so on.

<b>TCP-BASED TABLES</b>
       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 <a href="tcp_table.5.html"><b>tcp_table</b>(5)</a>.  This feature is not
       available up to and including Postfix version 2.4.

       Each lookup operation uses the entire address once.  Thus,  <i>user@domain</i>
       mail  addresses  are  not  broken  up  into their <i>user</i> and <i>@domain</i> con-
       stituent parts, nor is <i>user+foo</i> broken up into <i>user</i> and <i>foo</i>.

       Results are the same as with indexed file lookups.

<b>BUGS</b>
       The table format does not understand quoting conventions.

<b>CONFIGURATION PARAMETERS</b>
       The following <a href="postconf.5.html"><b>main.cf</b></a> parameters are  especially  relevant.   The  text
       below  provides  only  a  parameter  summary.  See <a href="postconf.5.html"><b>postconf</b>(5)</a> for more
       details including examples.

       <b><a href="postconf.5.html#canonical_classes">canonical_classes</a></b>
              What addresses are subject to canonical address mapping.

       <b><a href="postconf.5.html#canonical_maps">canonical_maps</a></b>
              List of canonical mapping tables.

       <b><a href="postconf.5.html#recipient_canonical_maps">recipient_canonical_maps</a></b>
              Address mapping lookup table for envelope and  header  recipient
              addresses.

       <b><a href="postconf.5.html#sender_canonical_maps">sender_canonical_maps</a></b>
              Address  mapping  lookup  table  for  envelope and header sender
              addresses.

       <b><a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a></b>
              A list of address rewriting or forwarding mechanisms that propa-
              gate  an  address  extension  from  the  original address to the
              result.  Specify zero or more of <b>canonical</b>, <b>virtual</b>, <b>alias</b>, <b>for-</b>
              <b>ward</b>, <b>include</b>, or <b>generic</b>.

       Other parameters of interest:

       <b><a href="postconf.5.html#inet_interfaces">inet_interfaces</a></b>
              The  network  interface addresses that this system receives mail
              on.  You need to stop and  start  Postfix  when  this  parameter
              changes.

       <b><a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a></b>
              Rewrite  message header addresses in mail from these clients and
              update incomplete addresses with the domain name in $<a href="postconf.5.html#myorigin">myorigin</a> or
              $<a href="postconf.5.html#mydomain">mydomain</a>;  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 <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_re</a>-
              <a href="postconf.5.html#remote_header_rewrite_domain">write_domain</a> parameter.

       <b><a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a></b>
              Other interfaces that this machine receives mail on by way of  a
              proxy agent or network address translator.

       <b><a href="postconf.5.html#masquerade_classes">masquerade_classes</a></b>
              List of address classes subject to masquerading: zero or more of
              <b>envelope_sender</b>,       <b>envelope_recipient</b>,        <b>header_sender</b>,
              <b>header_recipient</b>.

       <b><a href="postconf.5.html#masquerade_domains">masquerade_domains</a></b>
              List of domains that hide their subdomain structure.

       <b><a href="postconf.5.html#masquerade_exceptions">masquerade_exceptions</a></b>
              List of user names that are not subject to address masquerading.

       <b><a href="postconf.5.html#mydestination">mydestination</a></b>
              List of domains that this mail system considers local.

       <b><a href="postconf.5.html#myorigin">myorigin</a></b>
              The domain that is appended to locally-posted mail.

       <b><a href="postconf.5.html#owner_request_special">owner_request_special</a></b>
              Give special treatment to <b>owner-</b><i>xxx</i> and <i>xxx</i><b>-request</b> addresses.

       <b><a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a></b>
              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.

<b>SEE ALSO</b>
       <a href="cleanup.8.html">cleanup(8)</a>, canonicalize and enqueue mail
       <a href="postmap.1.html">postmap(1)</a>, Postfix lookup table manager
       <a href="postconf.5.html">postconf(5)</a>, configuration parameters
       <a href="virtual.5.html">virtual(5)</a>, virtual aliasing

<b>README FILES</b>
       <a href="DATABASE_README.html">DATABASE_README</a>, Postfix lookup table overview
       <a href="ADDRESS_REWRITING_README.html">ADDRESS_REWRITING_README</a>, address rewriting guide

<b>LICENSE</b>
       The Secure Mailer license must be distributed with this software.

<b>AUTHOR(S)</b>
       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

                                                                  CANONICAL(5)
</pre> </body> </html>