1# CANONICAL(5)                                                      CANONICAL(5)
2#
3# NAME
4#        canonical - Postfix canonical table format
5#
6# SYNOPSIS
7#        postmap /etc/postfix/canonical
8#
9#        postmap -q "string" /etc/postfix/canonical
10#
11#        postmap -q - /etc/postfix/canonical <inputfile
12#
13# DESCRIPTION
14#        The  optional canonical(5) table specifies an address map-
15#        ping for local and non-local  addresses.  The  mapping  is
16#        used  by the cleanup(8) daemon, before mail is stored into
17#        the queue.  The address mapping is recursive.
18#
19#        Normally, the canonical(5) table is specified  as  a  text
20#        file  that serves as input to the postmap(1) command.  The
21#        result, an indexed file in dbm or db format, is  used  for
22#        fast  searching  by  the  mail system. Execute the command
23#        "postmap /etc/postfix/canonical"  to  rebuild  an  indexed
24#        file after changing the corresponding text file.
25#
26#        When  the  table  is provided via other means such as NIS,
27#        LDAP or SQL, the same lookups are  done  as  for  ordinary
28#        indexed files.
29#
30#        Alternatively,  the  table  can  be provided as a regular-
31#        expression map where patterns are given as regular expres-
32#        sions,  or lookups can be directed to TCP-based server. In
33#        those cases, the lookups are done in a slightly  different
34#        way  as  described below under "REGULAR EXPRESSION TABLES"
35#        or "TCP-BASED TABLES".
36#
37#        By default the canonical(5) mapping affects  both  message
38#        header  addresses  (i.e. addresses that appear inside mes-
39#        sages) and message envelope addresses  (for  example,  the
40#        addresses  that  are used in SMTP protocol commands). This
41#        is controlled with the canonical_classes parameter.
42#
43#        NOTE: Postfix versions 2.2 and later rewrite message head-
44#        ers  from  remote  SMTP clients only if the client matches
45#        the  local_header_rewrite_clients  parameter,  or  if  the
46#        remote_header_rewrite_domain configuration parameter spec-
47#        ifies a non-empty value. To get the behavior before  Post-
48#        fix    2.2,    specify   "local_header_rewrite_clients   =
49#        static:all".
50#
51#        Typically, one would use the canonical(5) table to replace
52#        login   names   by  Firstname.Lastname,  or  to  clean  up
53#        addresses produced by legacy mail systems.
54#
55#        The canonical(5) mapping is not to be confused  with  vir-
56#        tual  alias  support or with local aliasing. To change the
57#        destination but not the headers,  use  the  virtual(5)  or
58#        aliases(5) map instead.
59#
60# CASE FOLDING
61#        The  search  string is folded to lowercase before database
62#        lookup. As of Postfix 2.3, the search string is  not  case
63#        folded  with database types such as regexp: or pcre: whose
64#        lookup fields can match both upper and lower case.
65#
66# TABLE FORMAT
67#        The input format for the postmap(1) command is as follows:
68#
69#        pattern result
70#               When  pattern matches a mail address, replace it by
71#               the corresponding result.
72#
73#        blank lines and comments
74#               Empty lines and whitespace-only lines are  ignored,
75#               as  are  lines whose first non-whitespace character
76#               is a `#'.
77#
78#        multi-line text
79#               A logical line starts with non-whitespace  text.  A
80#               line  that starts with whitespace continues a logi-
81#               cal line.
82#
83# TABLE SEARCH ORDER
84#        With lookups from indexed files such as DB or DBM, or from
85#        networked  tables  such  as NIS, LDAP or SQL, patterns are
86#        tried in the order as listed below:
87#
88#        user@domain address
89#               Replace user@domain by address. This form  has  the
90#               highest precedence.
91#
92#               This  is  useful  to clean up addresses produced by
93#               legacy mail systems.  It can also be used  to  pro-
94#               duce  Firstname.Lastname  style  addresses, but see
95#               below for a simpler solution.
96#
97#        user address
98#               Replace user@site by address when site is equal  to
99#               $myorigin,  when  site is listed in $mydestination,
100#               or  when  it  is  listed  in  $inet_interfaces   or
101#               $proxy_interfaces.
102#
103#               This  form  is  useful for replacing login names by
104#               Firstname.Lastname.
105#
106#        @domain address
107#               Replace other addresses in domain by address.  This
108#               form has the lowest precedence.
109#
110#               Note:  @domain  is  a  wild-card. When this form is
111#               applied to recipient addresses,  the  Postfix  SMTP
112#               server  accepts  mail  for any recipient in domain,
113#               regardless of whether that recipient exists.   This
114#               may  turn  your  mail  system  into  a  backscatter
115#               source: Postfix first accepts mail for non-existent
116#               recipients  and  then  tries to return that mail as
117#               "undeliverable" to the often forged sender address.
118#
119# RESULT ADDRESS REWRITING
120#        The lookup result is subject to address rewriting:
121#
122#        o      When  the  result  has  the  form @otherdomain, the
123#               result becomes the same user in otherdomain.
124#
125#        o      When "append_at_myorigin=yes", append  "@$myorigin"
126#               to addresses without "@domain".
127#
128#        o      When "append_dot_mydomain=yes", append ".$mydomain"
129#               to addresses without ".domain".
130#
131# ADDRESS EXTENSION
132#        When a mail address localpart contains the optional recip-
133#        ient  delimiter  (e.g., user+foo@domain), the lookup order
134#        becomes: user+foo@domain, user@domain, user+foo, user, and
135#        @domain.
136#
137#        The   propagate_unmatched_extensions   parameter  controls
138#        whether an unmatched address extension  (+foo)  is  propa-
139#        gated to the result of table lookup.
140#
141# REGULAR EXPRESSION TABLES
142#        This  section  describes how the table lookups change when
143#        the table is given in the form of regular expressions. For
144#        a  description  of regular expression lookup table syntax,
145#        see regexp_table(5) or pcre_table(5).
146#
147#        Each pattern is a regular expression that  is  applied  to
148#        the entire address being looked up. Thus, user@domain mail
149#        addresses are not broken up into their  user  and  @domain
150#        constituent parts, nor is user+foo broken up into user and
151#        foo.
152#
153#        Patterns are applied in the order as specified in the  ta-
154#        ble,  until  a  pattern  is  found that matches the search
155#        string.
156#
157#        Results are the same as with indexed  file  lookups,  with
158#        the  additional feature that parenthesized substrings from
159#        the pattern can be interpolated as $1, $2 and so on.
160#
161# TCP-BASED TABLES
162#        This section describes how the table lookups  change  when
163#        lookups are directed to a TCP-based server. For a descrip-
164#        tion of the TCP client/server lookup protocol, see tcp_ta-
165#        ble(5).  This feature is not available up to and including
166#        Postfix version 2.4.
167#
168#        Each lookup operation uses the entire address once.  Thus,
169#        user@domain  mail  addresses  are not broken up into their
170#        user and @domain constituent parts, nor is user+foo broken
171#        up into user and foo.
172#
173#        Results are the same as with indexed file lookups.
174#
175# BUGS
176#        The  table format does not understand quoting conventions.
177#
178# CONFIGURATION PARAMETERS
179#        The following main.cf parameters are especially  relevant.
180#        The  text  below  provides  only  a parameter summary. See
181#        postconf(5) for more details including examples.
182#
183#        canonical_classes
184#               What addresses are  subject  to  canonical  address
185#               mapping.
186#
187#        canonical_maps
188#               List of canonical mapping tables.
189#
190#        recipient_canonical_maps
191#               Address  mapping  lookup  table  for  envelope  and
192#               header recipient addresses.
193#
194#        sender_canonical_maps
195#               Address  mapping  lookup  table  for  envelope  and
196#               header sender addresses.
197#
198#        propagate_unmatched_extensions
199#               A  list  of  address rewriting or forwarding mecha-
200#               nisms that propagate an address extension from  the
201#               original  address  to  the result.  Specify zero or
202#               more  of  canonical,   virtual,   alias,   forward,
203#               include, or generic.
204#
205#        Other parameters of interest:
206#
207#        inet_interfaces
208#               The  network  interface  addresses that this system
209#               receives mail on.  You need to stop and start Post-
210#               fix when this parameter changes.
211#
212#        local_header_rewrite_clients
213#               Rewrite message header addresses in mail from these
214#               clients and update incomplete  addresses  with  the
215#               domain name in $myorigin or $mydomain; either don't
216#               rewrite message headers from other clients at  all,
217#               or  rewrite  message  headers and update incomplete
218#               addresses  with  the  domain   specified   in   the
219#               remote_header_rewrite_domain parameter.
220#
221#        proxy_interfaces
222#               Other interfaces that this machine receives mail on
223#               by way of a proxy agent or network address transla-
224#               tor.
225#
226#        masquerade_classes
227#               List  of  address  classes subject to masquerading:
228#               zero or more of  envelope_sender,  envelope_recipi-
229#               ent, header_sender, header_recipient.
230#
231#        masquerade_domains
232#               List  of  domains  that hide their subdomain struc-
233#               ture.
234#
235#        masquerade_exceptions
236#               List of user names that are not subject to  address
237#               masquerading.
238#
239#        mydestination
240#               List  of  domains  that  this mail system considers
241#               local.
242#
243#        myorigin
244#               The domain that is appended to locally-posted mail.
245#
246#        owner_request_special
247#               Give special treatment to owner-xxx and xxx-request
248#               addresses.
249#
250#        remote_header_rewrite_domain
251#               Don't rewrite message headers from  remote  clients
252#               at all when this parameter is empty; otherwise, re-
253#               write message  headers  and  append  the  specified
254#               domain name to incomplete addresses.
255#
256# SEE ALSO
257#        cleanup(8), canonicalize and enqueue mail
258#        postmap(1), Postfix lookup table manager
259#        postconf(5), configuration parameters
260#        virtual(5), virtual aliasing
261#
262# README FILES
263#        Use  "postconf  readme_directory" or "postconf html_direc-
264#        tory" to locate this information.
265#        DATABASE_README, Postfix lookup table overview
266#        ADDRESS_REWRITING_README, address rewriting guide
267#
268# LICENSE
269#        The Secure Mailer license must be  distributed  with  this
270#        software.
271#
272# AUTHOR(S)
273#        Wietse Venema
274#        IBM T.J. Watson Research
275#        P.O. Box 704
276#        Yorktown Heights, NY 10598, USA
277#
278#                                                                   CANONICAL(5)
279