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