<!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=utf-8">
<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> <<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 a 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 $<b><a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a></b>.
This form is useful for replacing login names by <i>Firstname.Last-</i>
<i>name</i>.
@<i>domain address</i>
Replace other addresses in <i>domain</i> by <i>address</i>. This form has the
lowest precedence.
Note: @<i>domain</i> is a wild-card. When this form is applied to
recipient addresses, the Postfix SMTP server accepts mail for
any recipient in <i>domain</i>, regardless of whether that recipient
exists. This may turn your mail system into a backscatter
source: Postfix first accepts mail for non-existent recipients
and then tries to return that mail as "undeliverable" to the
often forged sender address.
To avoid backscatter with mail for a wild-card domain, replace
the wild-card mapping with explicit 1:1 mappings, or add a
<a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a> restriction for that domain:
<a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> =
...
<a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a>
<a href="postconf.5.html#check_recipient_access">check_recipient_access</a>
<a href="DATABASE_README.html#types">inline</a>:{example.com=<a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a>}
<a href="postconf.5.html#unverified_recipient_reject_code">unverified_recipient_reject_code</a> = 550
In the above example, Postfix may contact a remote server if the
recipient is rewritten to a remote address.
<b>RESULT ADDRESS REWRITING</b>
The lookup result is subject to address rewriting:
<b>o</b> When the result has the form @<i>otherdomain</i>, the result becomes
the same <i>user</i> in <i>otherdomain</i>.
<b>o</b> When "<b><a href="postconf.5.html#append_at_myorigin">append_at_myorigin</a>=yes</b>", append "<b>@$<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> (envelope_sender, envelope_recipient, header_sender,</b>
<b>header_recipient)</b>
What addresses are subject to <a href="postconf.5.html#canonical_maps">canonical_maps</a> address mapping.
<b><a href="postconf.5.html#canonical_maps">canonical_maps</a> (empty)</b>
Optional address mapping lookup tables for message headers and
envelopes.
<b><a href="postconf.5.html#recipient_canonical_maps">recipient_canonical_maps</a> (empty)</b>
Optional address mapping lookup tables for envelope and header
recipient addresses.
<b><a href="postconf.5.html#sender_canonical_maps">sender_canonical_maps</a> (empty)</b>
Optional address mapping lookup tables for envelope and header
sender addresses.
<b><a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a> (canonical, virtual)</b>
What address lookup tables copy an address extension from the
lookup key to the lookup result.
Other parameters of interest:
<b><a href="postconf.5.html#inet_interfaces">inet_interfaces</a> (all)</b>
The network interface addresses that this mail system receives
mail on.
<b><a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> (<a href="postconf.5.html#permit_inet_interfaces">permit_inet_interfaces</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> (empty)</b>
The network interface addresses that this mail system receives
mail on by way of a proxy or network address translation unit.
<b><a href="postconf.5.html#masquerade_classes">masquerade_classes</a> (envelope_sender, header_sender, header_recipient)</b>
What addresses are subject to address masquerading.
<b><a href="postconf.5.html#masquerade_domains">masquerade_domains</a> (empty)</b>
Optional list of domains whose subdomain structure will be
stripped off in email addresses.
<b><a href="postconf.5.html#masquerade_exceptions">masquerade_exceptions</a> (empty)</b>
Optional list of user names that are not subjected to address
masquerading, even when their addresses match $<a href="postconf.5.html#masquerade_domains">masquer</a>-
<a href="postconf.5.html#masquerade_domains">ade_domains</a>.
<b><a href="postconf.5.html#mydestination">mydestination</a> ($<a href="postconf.5.html#myhostname">myhostname</a>, localhost.$<a href="postconf.5.html#mydomain">mydomain</a>, localhost)</b>
The list of domains that are delivered via the $<a href="postconf.5.html#local_transport">local_transport</a>
mail delivery transport.
<b><a href="postconf.5.html#myorigin">myorigin</a> ($<a href="postconf.5.html#myhostname">myhostname</a>)</b>
The domain name that locally-posted mail appears to come from,
and that locally posted mail is delivered to.
<b><a href="postconf.5.html#owner_request_special">owner_request_special</a> (yes)</b>
Enable special treatment for owner-<i>listname</i> entries in the
<a href="aliases.5.html"><b>aliases</b>(5)</a> file, and don't split owner-<i>listname</i> and <i>list-</i>
<i>name</i>-request address localparts when the <a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> is
set to "-".
<b><a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> (empty)</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>