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8ALIASES(5)                                                          ALIASES(5)
9
10<b>NAME</b>
11       aliases - Postfix local alias database format
12
13<b>SYNOPSIS</b>
14       <b>newaliases</b>
15
16<b>DESCRIPTION</b>
17       The  <a href="aliases.5.html"><b>aliases</b>(5)</a> table provides a system-wide mechanism to redirect mail
18       for local recipients. The redirections are  processed  by  the  Postfix
19       <a href="local.8.html"><b>local</b>(8)</a> delivery agent.
20
21       Normally,  the <a href="aliases.5.html"><b>aliases</b>(5)</a> table is specified as a text file that serves
22       as input to the <a href="postalias.1.html"><b>postalias</b>(1)</a> command. The result, an  indexed  file  in
23       <b>dbm</b>  or  <b>db</b> format, is used for fast lookup by the mail system. Execute
24       the command <b>newaliases</b> in order  to  rebuild  the  indexed  file  after
25       changing the Postfix alias database.
26
27       When  the  table  is provided via other means such as NIS, LDAP or SQL,
28       the same lookups are done as for ordinary indexed files.
29
30       Alternatively, the table can be provided as  a  regular-expression  map
31       where  patterns  are  given  as  regular expressions. In this case, the
32       lookups are done in a slightly different way as described  below  under
33       "REGULAR EXPRESSION TABLES".
34
35       Users  can  control  delivery  of their own mail by setting up <b>.forward</b>
36       files in their home directory.  Lines in per-user <b>.forward</b>  files  have
37       the same syntax as the right-hand side of <a href="aliases.5.html"><b>aliases</b>(5)</a> entries.
38
39       The format of the alias database input file is as follows:
40
41       <b>o</b>      An alias definition has the form
42
43                   <i>name</i>: <i>value1</i>, <i>value2</i>, <i>...</i>
44
45       <b>o</b>      Empty  lines and whitespace-only lines are ignored, as are lines
46              whose first non-whitespace character is a `#'.
47
48       <b>o</b>      A logical line starts with  non-whitespace  text.  A  line  that
49              starts with whitespace continues a logical line.
50
51       The  <i>name</i>  is a local address (no domain part).  Use double quotes when
52       the name contains any special characters such as whitespace, `#',  `:',
53       or  `@'.  The  <i>name</i>  is  folded to lowercase, in order to make database
54       lookups case insensitive.
55
56       In addition, when an alias exists for <b>owner-</b><i>name</i>,  this  will  override
57       the  envelope sender address, so that delivery diagnostics are directed
58       to <b>owner-</b><i>name</i>, instead of the originator of the message  (for  details,
59       see  <b><a href="postconf.5.html#owner_request_special">owner_request_special</a></b>,  <b><a href="postconf.5.html#expand_owner_alias">expand_owner_alias</a></b> and <b><a href="postconf.5.html#reset_owner_alias">reset_owner_alias</a></b>).
60       This is typically used to direct delivery errors to the maintainer of a
61       mailing  list,  who  is  in a better position to deal with mailing list
62       delivery problems than the originator of the undelivered mail.
63
64       The <i>value</i> contains one or more of the following:
65
66       <i>address</i>
67              Mail is forwarded to <i>address</i>, which is compatible with  the  <a href="https://tools.ietf.org/html/rfc822">RFC</a>
68              <a href="https://tools.ietf.org/html/rfc822">822</a> standard.
69
70       <i>/file/name</i>
71              Mail  is  appended  to  <i>/file/name</i>. For details on how a file is
72              written see the sections "EXTERNAL FILE DELIVERY" and  "DELIVERY
73              RIGHTS"  in the <a href="local.8.html"><b>local</b>(8)</a> documentation.  Delivery is not limited
74              to regular files.  For example, to  dispose  of  unwanted  mail,
75              deflect it to <b>/dev/null</b>.
76
77       |<i>command</i>
78              Mail  is piped into <i>command</i>. Commands that contain special char-
79              acters, such as whitespace, should be  enclosed  between  double
80              quotes.  For  details on how a command is executed see "EXTERNAL
81              COMMAND DELIVERY" and "DELIVERY RIGHTS" in the <a href="local.8.html"><b>local</b>(8)</a> documen-
82              tation.
83
84              When  the  command  fails, a limited amount of command output is
85              mailed back to the  sender.   The  file  <b>/usr/include/sysexits.h</b>
86              defines  the expected exit status codes. For example, use <b>"|exit</b>
87              <b>67"</b> to simulate a "user unknown" error, and <b>"|exit 0"</b> to  imple-
88              ment an expensive black hole.
89
90       <b>:include:</b><i>/file/name</i>
91              Mail  is  sent  to  the  destinations  listed in the named file.
92              Lines in <b>:include:</b> files have the same syntax as the  right-hand
93              side of alias entries.
94
95              A  destination  can be any destination that is described in this
96              manual page. However, delivery to "|<i>command</i>" and  <i>/file/name</i>  is
97              disallowed  by  default.  To enable, edit the <b><a href="postconf.5.html#allow_mail_to_commands">allow_mail_to_com</a>-</b>
98              <b><a href="postconf.5.html#allow_mail_to_commands">mands</a></b> and <b><a href="postconf.5.html#allow_mail_to_files">allow_mail_to_files</a></b> configuration parameters.
99
100<b>ADDRESS EXTENSION</b>
101       When alias database search fails, and the recipient localpart  contains
102       the  optional  recipient  delimiter  (e.g.,  <i>user+foo</i>),  the  search is
103       repeated for the unextended address (e.g., <i>user</i>).
104
105       The  <b><a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a></b>  parameter  controls   whether   an
106       unmatched address extension (<i>+foo</i>) is propagated to the result of table
107       lookup.
108
109<b>CASE FOLDING</b>
110       The <a href="local.8.html">local(8)</a> delivery agent always folds the search string to lowercase
111       before database lookup.
112
113<b>REGULAR EXPRESSION TABLES</b>
114       This  section  describes how the table lookups change when the table is
115       given in the form of regular expressions. For a description of  regular
116       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>.
117       NOTE: these formats do not use ":" at the end of a pattern.
118
119       Each regular expression is applied to the entire search string. Thus, a
120       search string <i>user+foo</i> is not broken up into <i>user</i> and <i>foo</i>.
121
122       Regular expressions are applied in the order as specified in the table,
123       until a regular expression is found that matches the search string.
124
125       Lookup results are the same as with indexed file lookups.  For security
126       reasons there is no support for <b>$1</b>, <b>$2</b> etc. substring interpolation.
127
128<b>SECURITY</b>
129       The  <a href="local.8.html"><b>local</b>(8)</a>  delivery agent disallows regular expression substitution
130       of $1 etc. in <b><a href="postconf.5.html#alias_maps">alias_maps</a></b>, because that would open a security hole.
131
132       The <a href="local.8.html"><b>local</b>(8)</a> delivery agent will silently ignore requests  to  use  the
133       <a href="proxymap.8.html"><b>proxymap</b>(8)</a>  server  within  <b><a href="postconf.5.html#alias_maps">alias_maps</a></b>. Instead it will open the table
134       directly.  Before Postfix version 2.2, the <a href="local.8.html"><b>local</b>(8)</a> delivery agent will
135       terminate with a fatal error.
136
137<b>CONFIGURATION PARAMETERS</b>
138       The  following  <a href="postconf.5.html"><b>main.cf</b></a>  parameters  are especially relevant.  The text
139       below provides only a  parameter  summary.  See  <a href="postconf.5.html"><b>postconf</b>(5)</a>  for  more
140       details including examples.
141
142       <b><a href="postconf.5.html#alias_database">alias_database</a> (see 'postconf -d' output)</b>
143              The  alias databases for <a href="local.8.html"><b>local</b>(8)</a> delivery that are updated with
144              "<b>newaliases</b>" or with "<b>sendmail -bi</b>".
145
146       <b><a href="postconf.5.html#alias_maps">alias_maps</a> (see 'postconf -d' output)</b>
147              The alias databases that are used for <a href="local.8.html"><b>local</b>(8)</a> delivery.
148
149       <b><a href="postconf.5.html#allow_mail_to_commands">allow_mail_to_commands</a> (alias, forward)</b>
150              Restrict <a href="local.8.html"><b>local</b>(8)</a> mail delivery to external commands.
151
152       <b><a href="postconf.5.html#allow_mail_to_files">allow_mail_to_files</a> (alias, forward)</b>
153              Restrict <a href="local.8.html"><b>local</b>(8)</a> mail delivery to external files.
154
155       <b><a href="postconf.5.html#expand_owner_alias">expand_owner_alias</a> (no)</b>
156              When  delivering  to  an   alias   "<i>aliasname</i>"   that   has   an
157              "owner-<i>aliasname</i>"  companion  alias,  set  the  envelope  sender
158              address to the expansion of the "owner-<i>aliasname</i>" alias.
159
160       <b><a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a> (canonical, virtual)</b>
161              What address lookup tables copy an address  extension  from  the
162              lookup key to the lookup result.
163
164       <b><a href="postconf.5.html#owner_request_special">owner_request_special</a> (yes)</b>
165              Enable  special  treatment  for  owner-<i>listname</i>  entries  in the
166              <a href="aliases.5.html"><b>aliases</b>(5)</a>  file,  and  don't  split  owner-<i>listname</i>  and  <i>list-</i>
167              <i>name</i>-request  address localparts when the <a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> is
168              set to "-".
169
170       <b><a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> (empty)</b>
171              The set of characters that can separate an email address  local-
172              part, user name, or a .forward file name from its extension.
173
174       Available in Postfix version 2.3 and later:
175
176       <b><a href="postconf.5.html#frozen_delivered_to">frozen_delivered_to</a> (yes)</b>
177              Update  the  <a href="local.8.html"><b>local</b>(8)</a> delivery agent's idea of the Delivered-To:
178              address (see <a href="postconf.5.html#prepend_delivered_header">prepend_delivered_header</a>) only once, at  the  start
179              of  a  delivery attempt; do not update the Delivered-To: address
180              while expanding aliases or .forward files.
181
182<b>STANDARDS</b>
183       <a href="https://tools.ietf.org/html/rfc822">RFC 822</a> (ARPA Internet Text Messages)
184
185<b>SEE ALSO</b>
186       <a href="local.8.html">local(8)</a>, local delivery agent
187       <a href="newaliases.1.html">newaliases(1)</a>, create/update alias database
188       <a href="postalias.1.html">postalias(1)</a>, create/update alias database
189       <a href="postconf.5.html">postconf(5)</a>, configuration parameters
190
191<b>README FILES</b>
192       <a href="DATABASE_README.html">DATABASE_README</a>, Postfix lookup table overview
193
194<b>LICENSE</b>
195       The Secure Mailer license must be distributed with this software.
196
197<b>AUTHOR(S)</b>
198       Wietse Venema
199       IBM T.J. Watson Research
200       P.O. Box 704
201       Yorktown Heights, NY 10598, USA
202
203       Wietse Venema
204       Google, Inc.
205       111 8th Avenue
206       New York, NY 10011, USA
207
208                                                                    ALIASES(5)
209</pre> </body> </html>
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