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
14 local(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
57 delivery 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. See local(8) for details of
67 delivery to file. Delivery is not limited to regular files.
68 For example, to dispose of unwanted mail, deflect it to
69 /dev/null.
70 |command
72 Mail is piped into command. Commands that contain special char‐
73 acters, such as whitespace, should be enclosed between double
74 quotes. See local(8) for details of delivery to command.
75 When the command fails, a limited amount of command output is
77 mailed back to the sender. The file /usr/include/sysexits.h
78 defines the expected exit status codes. For example, use "|exit
79 67" to simulate a "user unknown" error, and "|exit 0" to imple‐
80 ment an expensive black hole.
81 :include:/file/name
83 Mail is sent to the destinations listed in the named file.
84 Lines in :include: files have the same syntax as the right-hand
85 side of alias entries.
86 A destination can be any destination that is described in this
88 manual page. However, delivery to "|command" and /file/name is
89 disallowed by default. To enable, edit the allow_mail_to_com‐
90 mands and allow_mail_to_files configuration parameters.
91
93 When alias database search fails, and the recipient localpart contains
94 the optional recipient delimiter (e.g., user+foo), the search is
95 repeated for the unextended address (e.g., user).
96 The propagate_unmatched_extensions parameter controls whether an
98 unmatched address extension (+foo) is propagated to the result of table
99 lookup.
100
102 The local(8) delivery agent always folds the search string to lowercase
103 before database lookup.
104
106 This section describes how the table lookups change when the table is
107 given in the form of regular expressions. For a description of regular
108 expression lookup table syntax, see regexp_table(5) or pcre_table(5).
109 NOTE: these formats do not use ":" at the end of a pattern.
110 Each regular expression is applied to the entire search string. Thus, a
112 search string user+foo is not broken up into user and foo.
113 Regular expressions are applied in the order as specified in the table,
115 until a regular expression is found that matches the search string.
116 Lookup results are the same as with indexed file lookups. For security
118 reasons there is no support for $1, $2 etc. substring interpolation.
119
121 The local(8) delivery agent disallows regular expression substitution
122 of $1 etc. in alias_maps, because that would open a security hole.
123 The local(8) delivery agent will silently ignore requests to use the
125 proxymap(8) server within alias_maps. Instead it will open the table
126 directly. Before Postfix version 2.2, the local(8) delivery agent will
127 terminate with a fatal error.
128
130 The following main.cf parameters are especially relevant. The text
131 below provides only a parameter summary. See postconf(5) for more
132 details including examples.
133 alias_database (see 'postconf -d' output)
135 The alias databases for local(8) delivery that are updated with
136 "newaliases" or with "sendmail -bi".
137 alias_maps (see 'postconf -d' output)
139 The alias databases that are used for local(8) delivery.
140 allow_mail_to_commands (alias, forward)
142 Restrict local(8) mail delivery to external commands.
143 allow_mail_to_files (alias, forward)
145 Restrict local(8) mail delivery to external files.
146 expand_owner_alias (no)
148 When delivering to an alias "aliasname" that has an
149 "owner-aliasname" companion alias, set the envelope sender
150 address to the expansion of the "owner-aliasname" alias.
151 propagate_unmatched_extensions (canonical, virtual)
153 What address lookup tables copy an address extension from the
154 lookup key to the lookup result.
155 owner_request_special (yes)
157 Enable special treatment for owner-listname entries in the
158 aliases(5) file, and don't split owner-listname and list‐
159 name-request address localparts when the recipient_delimiter is
160 set to "-".
161 recipient_delimiter (empty)
163 The set of characters that can separate a user name from its
164 extension (example: user+foo), or a .forward file name from its
165 extension (example: .forward+foo).
166 Available in Postfix version 2.3 and later:
168 frozen_delivered_to (yes)
170 Update the local(8) delivery agent's idea of the Delivered-To:
171 address (see prepend_delivered_header) only once, at the start
172 of a delivery attempt; do not update the Delivered-To: address
173 while expanding aliases or .forward files.
174
176 RFC 822 (ARPA Internet Text Messages)
177
179 local(8), local delivery agent
180 newaliases(1), create/update alias database
181 postalias(1), create/update alias database
182 postconf(5), configuration parameters
183
185 Use "postconf readme_directory" or "postconf html_directory" to locate
186 this information.
187 DATABASE_README, Postfix lookup table overview
188
190 The Secure Mailer license must be distributed with this software.
191
193 Wietse Venema
194 IBM T.J. Watson Research
195 P.O. Box 704
196 Yorktown Heights, NY 10598, USA
197 Wietse Venema
199 Google, Inc.
200 111 8th Avenue
201 New York, NY 10011, USA
202 ALIASES(5)