1ALIASES(5)                    File Formats Manual                   ALIASES(5)
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NAME

6       aliases - Postfix local alias database format
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SYNOPSIS

9       newaliases
10

DESCRIPTION

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
16       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
22       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
25       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".
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30       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.
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34       The format of the alias database input file is as follows:
35
36       ·      An alias definition has the form
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38                   name: value1, value2, ...
39
40       ·      Empty  lines and whitespace-only lines are ignored, as are lines
41              whose first non-whitespace character is a `#'.
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43       ·      A logical line starts with  non-whitespace  text.  A  line  that
44              starts with whitespace continues a logical line.
45
46       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.
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51       In addition, when an alias exists for owner-name, delivery  diagnostics
52       are  directed to that address, instead of to the originator of the mes‐
53       sage.  This is typically used to direct delivery errors  to  the  main‐
54       tainer  of  a  mailing  list,  who is in a better position to deal with
55       mailing list delivery problems than the originator of  the  undelivered
56       mail.
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58       The value contains one or more of the following:
59
60       address
61              Mail  is  forwarded to address, which is compatible with the RFC
62              822 standard.
63
64       /file/name
65              Mail is appended to /file/name.  See  local(8)  for  details  of
66              delivery  to  file.   Delivery  is not limited to regular files.
67              For  example,  to  dispose  of  unwanted  mail,  deflect  it  to
68              /dev/null.
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70       |command
71              Mail  is piped into command. Commands that contain special char‐
72              acters, such as whitespace, should be  enclosed  between  double
73              quotes. See local(8) for details of delivery to command.
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75              When  the  command  fails, a limited amount of command output is
76              mailed back to the  sender.   The  file  /usr/include/sysexits.h
77              defines  the expected exit status codes. For example, use "|exit
78              67" to simulate a "user unknown" error, and "|exit 0" to  imple‐
79              ment an expensive black hole.
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81       :include:/file/name
82              Mail  is  sent  to  the  destinations  listed in the named file.
83              Lines in :include: files have the same syntax as the  right-hand
84              side of alias entries.
85
86              A  destination  can be any destination that is described in this
87              manual page. However, delivery to "|command" and  /file/name  is
88              disallowed  by  default.  To enable, edit the allow_mail_to_com‐
89              mands and allow_mail_to_files configuration parameters.
90

ADDRESS EXTENSION

92       When alias database search fails, and the recipient localpart  contains
93       the  optional  recipient  delimiter  (e.g.,  user+foo),  the  search is
94       repeated for the unextended address (e.g., user).
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96       The  propagate_unmatched_extensions  parameter  controls   whether   an
97       unmatched address extension (+foo) is propagated to the result of table
98       lookup.
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CASE FOLDING

101       The local(8) delivery agent always folds the search string to lowercase
102       before database lookup.
103

REGULAR EXPRESSION TABLES

105       This  section  describes how the table lookups change when the table is
106       given in the form of regular expressions. For a description of  regular
107       expression  lookup  table syntax, see regexp_table(5) or pcre_table(5).
108       NOTE: these formats do not use ":" at the end of a pattern.
109
110       Each regular expression is applied to the entire search string. Thus, a
111       search string user+foo is not broken up into user and foo.
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113       Regular expressions are applied in the order as specified in the table,
114       until a regular expression is found that matches the search string.
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116       Lookup results are the same as with indexed file lookups.  For security
117       reasons there is no support for $1, $2 etc. substring interpolation.
118

SECURITY

120       The  local(8)  delivery agent disallows regular expression substitution
121       of $1 etc. in alias_maps, because that would open a security hole.
122
123       The local(8) delivery agent will silently ignore requests  to  use  the
124       proxymap(8)  server  within  alias_maps. Instead it will open the table
125       directly.  Before Postfix version 2.2, the local(8) delivery agent will
126       terminate with a fatal error.
127

CONFIGURATION PARAMETERS

129       The  following  main.cf  parameters  are especially relevant.  The text
130       below provides only a  parameter  summary.  See  postconf(5)  for  more
131       details including examples.
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133       alias_database
134              List  of  alias  databases that are updated by the newaliases(1)
135              command.
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137       alias_maps
138              List of alias databases queried by the local(8) delivery agent.
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140       allow_mail_to_commands
141              Restrict the usage of mail delivery to external command.
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143       allow_mail_to_files
144              Restrict the usage of mail delivery to external file.
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146       expand_owner_alias
147              When delivering to an alias that has an owner- companion  alias,
148              set  the  envelope  sender address to the right-hand side of the
149              owner alias, instead using of the left-hand side address.
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151       propagate_unmatched_extensions
152              A list of address rewriting or forwarding mechanisms that propa‐
153              gate  an  address  extension  from  the  original address to the
154              result. Specify zero or more of canonical, virtual, alias,  for‐
155              ward, include, or generic.
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157       owner_request_special
158              Give  special  treatment  to owner-listname and listname-request
159              addresses.
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161       recipient_delimiter
162              Delimiter that separates recipients from address extensions.
163
164       Available in Postfix version 2.3 and later:
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166       frozen_delivered_to
167              Update the local(8) delivery agent's Delivered-To: address  (see
168              prepend_delivered_header) only once, at the start of a delivery;
169              do not update the Delivered-To: address while expanding  aliases
170              or .forward files.
171

STANDARDS

173       RFC 822 (ARPA Internet Text Messages)
174

SEE ALSO

176       local(8), local delivery agent
177       newaliases(1), create/update alias database
178       postalias(1), create/update alias database
179       postconf(5), configuration parameters
180

README FILES

182       Use  "postconf readme_directory" or "postconf html_directory" to locate
183       this information.
184       DATABASE_README, Postfix lookup table overview
185

LICENSE

187       The Secure Mailer license must be distributed with this software.
188

AUTHOR(S)

190       Wietse Venema
191       IBM T.J. Watson Research
192       P.O. Box 704
193       Yorktown Heights, NY 10598, USA
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