xref: /netbsd-src/external/ibm-public/postfix/dist/html/canonical.5.html (revision 059c16a85b0b39d60ad6d18f53c09510815afa2b)
1<!doctype html public "-//W3C//DTD HTML 4.01 Transitional//EN"
2        "http://www.w3.org/TR/html4/loose.dtd">
3<html> <head>
4<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
5<link rel='stylesheet' type='text/css' href='postfix-doc.css'>
6<title> Postfix manual - canonical(5) </title>
7</head> <body> <pre>
8CANONICAL(5)                                                      CANONICAL(5)
9
10<b>NAME</b>
11       canonical - Postfix canonical table format
12
13<b>SYNOPSIS</b>
14       <b>postmap /etc/postfix/canonical</b>
15
16       <b>postmap -q "</b><i>string</i><b>" /etc/postfix/canonical</b>
17
18       <b>postmap -q - /etc/postfix/canonical</b> &lt;<i>inputfile</i>
19
20<b>DESCRIPTION</b>
21       The  optional <a href="canonical.5.html"><b>canonical</b>(5)</a> table specifies an address mapping for local
22       and non-local addresses. The mapping is used by the <a href="cleanup.8.html"><b>cleanup</b>(8)</a>  daemon,
23       before  mail  is  stored into the queue.  The address mapping is recur-
24       sive.
25
26       Normally, the <a href="canonical.5.html"><b>canonical</b>(5)</a> table is  specified  as  a  text  file  that
27       serves as input to the <a href="postmap.1.html"><b>postmap</b>(1)</a> command.  The result, an indexed file
28       in <b>dbm</b> or <b>db</b> format, is used for fast searching  by  the  mail  system.
29       Execute  the  command  "<b>postmap  /etc/postfix/canonical</b>"  to rebuild an
30       indexed file after changing the corresponding text file.
31
32       When the table is provided via other means such as NIS,  LDAP  or  SQL,
33       the same lookups are done as for ordinary indexed files.
34
35       Alternatively,  the  table  can be provided as a regular-expression map
36       where patterns are given as regular  expressions,  or  lookups  can  be
37       directed to a TCP-based server. In those cases, the lookups are done in
38       a slightly different way as described below under  "REGULAR  EXPRESSION
39       TABLES" or "TCP-BASED TABLES".
40
41       By  default  the  <a href="canonical.5.html"><b>canonical</b>(5)</a>  mapping  affects  both  message  header
42       addresses (i.e. addresses that  appear  inside  messages)  and  message
43       envelope  addresses  (for  example, the addresses that are used in SMTP
44       protocol commands).  This  is  controlled  with  the  <b><a href="postconf.5.html#canonical_classes">canonical_classes</a></b>
45       parameter.
46
47       NOTE:  Postfix  versions  2.2  and  later  rewrite message headers from
48       remote SMTP clients only if the  client  matches  the  <a href="postconf.5.html#local_header_rewrite_clients">local_header_re</a>-
49       <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-
50       uration parameter specifies a non-empty  value.  To  get  the  behavior
51       before    Postfix    2.2,   specify   "<a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a>   =
52       <a href="DATABASE_README.html#types">static</a>:all".
53
54       Typically, one would use the <a href="canonical.5.html"><b>canonical</b>(5)</a> table to replace login  names
55       by <i>Firstname.Lastname</i>, or to clean up addresses produced by legacy mail
56       systems.
57
58       The <a href="canonical.5.html"><b>canonical</b>(5)</a> mapping is not to be confused with <i>virtual alias</i>  sup-
59       port  or  with  local  aliasing.  To change the destination but not the
60       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.
61
62<b>CASE FOLDING</b>
63       The search string is folded to lowercase before database lookup. As  of
64       Postfix  2.3,  the search string is not case folded with database types
65       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
66       lower case.
67
68<b>TABLE FORMAT</b>
69       The input format for the <a href="postmap.1.html"><b>postmap</b>(1)</a> command is as follows:
70
71       <i>pattern address</i>
72              When  <i>pattern</i>  matches  a mail address, replace it by the corre-
73              sponding <i>address</i>.
74
75       blank lines and comments
76              Empty lines and whitespace-only lines are ignored, as are  lines
77              whose first non-whitespace character is a `#'.
78
79       multi-line text
80              A  logical  line  starts  with  non-whitespace text. A line that
81              starts with whitespace continues a logical line.
82
83<b>TABLE SEARCH ORDER</b>
84       With lookups from indexed files such as DB or DBM,  or  from  networked
85       tables  such  as  NIS,  LDAP  or SQL, each <i>user</i>@<i>domain</i> query produces a
86       sequence of query patterns as described below.
87
88       Each query pattern is sent to each specified lookup table before trying
89       the next query pattern, until a match is found.
90
91       <i>user</i>@<i>domain address</i>
92              Replace <i>user</i>@<i>domain</i> by <i>address</i>. This form has the highest prece-
93              dence.
94
95              This is useful to clean up addresses  produced  by  legacy  mail
96              systems.   It  can  also  be  used to produce <i>Firstname.Lastname</i>
97              style addresses, but see below for a simpler solution.
98
99       <i>user address</i>
100              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>,
101              when  <i>site</i>  is listed in $<b><a href="postconf.5.html#mydestination">mydestination</a></b>, or when it is listed in
102              $<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>.
103
104              This form is useful for replacing login names by <i>Firstname.Last-</i>
105              <i>name</i>.
106
107       @<i>domain address</i>
108              Replace other addresses in <i>domain</i> by <i>address</i>.  This form has the
109              lowest precedence.
110
111              Note: @<i>domain</i> is a wild-card.  When  this  form  is  applied  to
112              recipient  addresses,  the  Postfix SMTP server accepts mail for
113              any recipient in <i>domain</i>, regardless of  whether  that  recipient
114              exists.   This  may  turn  your  mail  system into a backscatter
115              source: Postfix first accepts mail for  non-existent  recipients
116              and  then  tries  to  return that mail as "undeliverable" to the
117              often forged sender address.
118
119              To avoid backscatter with mail for a wild-card  domain,  replace
120              the  wild-card  mapping  with  explicit  1:1  mappings, or add a
121              <a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a> restriction for that domain:
122
123                  <a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> =
124                      ...
125                      <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a>
126                      <a href="postconf.5.html#check_recipient_access">check_recipient_access</a>
127                          <a href="DATABASE_README.html#types">inline</a>:{example.com=<a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a>}
128                  <a href="postconf.5.html#unverified_recipient_reject_code">unverified_recipient_reject_code</a> = 550
129
130              In the above example, Postfix may contact a remote server if the
131              recipient is rewritten to a remote address.
132
133<b>RESULT ADDRESS REWRITING</b>
134       The lookup result is subject to address rewriting:
135
136       <b>o</b>      When  the  result  has the form @<i>otherdomain</i>, the result becomes
137              the same <i>user</i> in <i>otherdomain</i>.
138
139       <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
140              without "@domain".
141
142       <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
143              without ".domain".
144
145<b>ADDRESS EXTENSION</b>
146       When a mail address localpart contains the optional recipient delimiter
147       (e.g.,  <i>user+foo</i>@<i>domain</i>),  the  lookup  order becomes: <i>user+foo</i>@<i>domain</i>,
148       <i>user</i>@<i>domain</i>, <i>user+foo</i>, <i>user</i>, and @<i>domain</i>.
149
150       The  <b><a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a></b>  parameter  controls   whether   an
151       unmatched address extension (<i>+foo</i>) is propagated to the result of table
152       lookup.
153
154<b>REGULAR EXPRESSION TABLES</b>
155       This section describes how the table lookups change when the  table  is
156       given  in the form of regular expressions. For a description of regular
157       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>.
158
159       Each pattern is a regular expression that  is  applied  to  the  entire
160       address  being looked up. Thus, <i>user@domain</i> mail addresses are not bro-
161       ken up into their <i>user</i> and <i>@domain</i> constituent parts, nor  is  <i>user+foo</i>
162       broken up into <i>user</i> and <i>foo</i>.
163
164       Patterns  are  applied  in the order as specified in the table, until a
165       pattern is found that matches the search string.
166
167       Results are the same as with indexed file lookups, with the  additional
168       feature  that parenthesized substrings from the pattern can be interpo-
169       lated as <b>$1</b>, <b>$2</b> and so on.
170
171<b>TCP-BASED TABLES</b>
172       This section describes how the table lookups change  when  lookups  are
173       directed   to  a  TCP-based  server.  For  a  description  of  the  TCP
174       client/server lookup protocol, see <a href="tcp_table.5.html"><b>tcp_table</b>(5)</a>.  This feature  is  not
175       available up to and including Postfix version 2.4.
176
177       Each  lookup operation uses the entire address once.  Thus, <i>user@domain</i>
178       mail addresses are not broken up  into  their  <i>user</i>  and  <i>@domain</i>  con-
179       stituent parts, nor is <i>user+foo</i> broken up into <i>user</i> and <i>foo</i>.
180
181       Results are the same as with indexed file lookups.
182
183<b>BUGS</b>
184       The table format does not understand quoting conventions.
185
186<b>CONFIGURATION PARAMETERS</b>
187       The  following  <a href="postconf.5.html"><b>main.cf</b></a>  parameters  are especially relevant.  The text
188       below provides only a  parameter  summary.  See  <a href="postconf.5.html"><b>postconf</b>(5)</a>  for  more
189       details including examples.
190
191       <b><a href="postconf.5.html#canonical_classes">canonical_classes</a>  (envelope_sender, envelope_recipient, header_sender,</b>
192       <b>header_recipient)</b>
193              What addresses are subject to <a href="postconf.5.html#canonical_maps">canonical_maps</a> address mapping.
194
195       <b><a href="postconf.5.html#canonical_maps">canonical_maps</a> (empty)</b>
196              Optional  address  mapping lookup tables for message headers and
197              envelopes.
198
199       <b><a href="postconf.5.html#recipient_canonical_maps">recipient_canonical_maps</a> (empty)</b>
200              Optional address mapping lookup tables for envelope  and  header
201              recipient addresses.
202
203       <b><a href="postconf.5.html#sender_canonical_maps">sender_canonical_maps</a> (empty)</b>
204              Optional  address  mapping lookup tables for envelope and header
205              sender addresses.
206
207       <b><a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a> (canonical, virtual)</b>
208              What address lookup tables copy an address  extension  from  the
209              lookup key to the lookup result.
210
211       Other parameters of interest:
212
213       <b><a href="postconf.5.html#inet_interfaces">inet_interfaces</a> (all)</b>
214              The  network  interface addresses that this mail system receives
215              mail on.
216
217       <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>
218              Rewrite message header addresses in mail from these clients  and
219              update incomplete addresses with the domain name in $<a href="postconf.5.html#myorigin">myorigin</a> or
220              $<a href="postconf.5.html#mydomain">mydomain</a>; either  don't  rewrite  message  headers  from  other
221              clients at all, or rewrite message headers and update incomplete
222              addresses with the domain  specified  in  the  <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_re</a>-
223              <a href="postconf.5.html#remote_header_rewrite_domain">write_domain</a> parameter.
224
225       <b><a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a> (empty)</b>
226              The  network  interface addresses that this mail system receives
227              mail on by way of a proxy or network address translation unit.
228
229       <b><a href="postconf.5.html#masquerade_classes">masquerade_classes</a> (envelope_sender, header_sender, header_recipient)</b>
230              What addresses are subject to address masquerading.
231
232       <b><a href="postconf.5.html#masquerade_domains">masquerade_domains</a> (empty)</b>
233              Optional list of  domains  whose  subdomain  structure  will  be
234              stripped off in email addresses.
235
236       <b><a href="postconf.5.html#masquerade_exceptions">masquerade_exceptions</a> (empty)</b>
237              Optional  list  of  user names that are not subjected to address
238              masquerading,  even  when  their   addresses   match   $<a href="postconf.5.html#masquerade_domains">masquer</a>-
239              <a href="postconf.5.html#masquerade_domains">ade_domains</a>.
240
241       <b><a href="postconf.5.html#mydestination">mydestination</a> ($<a href="postconf.5.html#myhostname">myhostname</a>, localhost.$<a href="postconf.5.html#mydomain">mydomain</a>, localhost)</b>
242              The  list of domains that are delivered via the $<a href="postconf.5.html#local_transport">local_transport</a>
243              mail delivery transport.
244
245       <b><a href="postconf.5.html#myorigin">myorigin</a> ($<a href="postconf.5.html#myhostname">myhostname</a>)</b>
246              The domain name that locally-posted mail appears to  come  from,
247              and that locally posted mail is delivered to.
248
249       <b><a href="postconf.5.html#owner_request_special">owner_request_special</a> (yes)</b>
250              Enable  special  treatment  for  owner-<i>listname</i>  entries  in the
251              <a href="aliases.5.html"><b>aliases</b>(5)</a>  file,  and  don't  split  owner-<i>listname</i>  and  <i>list-</i>
252              <i>name</i>-request  address localparts when the <a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> is
253              set to "-".
254
255       <b><a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> (empty)</b>
256              Don't rewrite message headers from remote clients  at  all  when
257              this  parameter is empty; otherwise, rewrite message headers and
258              append the specified domain name to incomplete addresses.
259
260<b>SEE ALSO</b>
261       <a href="cleanup.8.html">cleanup(8)</a>, canonicalize and enqueue mail
262       <a href="postmap.1.html">postmap(1)</a>, Postfix lookup table manager
263       <a href="postconf.5.html">postconf(5)</a>, configuration parameters
264       <a href="virtual.5.html">virtual(5)</a>, virtual aliasing
265
266<b>README FILES</b>
267       <a href="DATABASE_README.html">DATABASE_README</a>, Postfix lookup table overview
268       <a href="ADDRESS_REWRITING_README.html">ADDRESS_REWRITING_README</a>, address rewriting guide
269
270<b>LICENSE</b>
271       The Secure Mailer license must be distributed with this software.
272
273<b>AUTHOR(S)</b>
274       Wietse Venema
275       IBM T.J. Watson Research
276       P.O. Box 704
277       Yorktown Heights, NY 10598, USA
278
279       Wietse Venema
280       Google, Inc.
281       111 8th Avenue
282       New York, NY 10011, USA
283
284                                                                  CANONICAL(5)
285</pre> </body> </html>
286