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GENERIC(5) GENERIC(5)
<b>NAME</b>
generic - Postfix generic table format
<b>SYNOPSIS</b>
<b>postmap /etc/postfix/generic</b>
<b>postmap -q "</b><i>string</i><b>" /etc/postfix/generic</b>
<b>postmap -q - /etc/postfix/generic</b> <<i>inputfile</i>
<b>DESCRIPTION</b>
The optional <a href="generic.5.html"><b>generic</b>(5)</a> table specifies an address mapping that applies
when mail is delivered. This is the opposite of <a href="canonical.5.html"><b>canonical</b>(5)</a> mapping,
which applies when mail is received.
Typically, one would use the <a href="generic.5.html"><b>generic</b>(5)</a> table on a system that does not
have a valid Internet domain name and that uses something like <i>localdo-</i>
<i>main.local</i> instead. The <a href="generic.5.html"><b>generic</b>(5)</a> table is then used by the <a href="smtp.8.html"><b>smtp</b>(8)</a>
client to transform local mail addresses into valid Internet mail
addresses when mail has to be sent across the Internet. See the EXAM-
PLE section at the end of this document.
The <a href="generic.5.html"><b>generic</b>(5)</a> mapping affects both message header addresses (i.e.
addresses that appear inside messages) and message envelope addresses
(for example, the addresses that are used in SMTP protocol commands).
Normally, the <a href="generic.5.html"><b>generic</b>(5)</a> table is specified as a text file that serves
as input to the <a href="postmap.1.html"><b>postmap</b>(1)</a> command. The result, an indexed file in <b>dbm</b>
or <b>db</b> format, is used for fast searching by the mail system. Execute
the command "<b>postmap /etc/postfix/generic</b>" to rebuild an indexed file
after changing the corresponding text file.
When the table is provided via other means such as NIS, LDAP or SQL,
the same lookups are done as for ordinary indexed files.
Alternatively, the table can be provided as a regular-expression map
where patterns are given as regular expressions, or lookups can be
directed to TCP-based server. In those case, the lookups are done in a
slightly different way as described below under "REGULAR EXPRESSION
TABLES" or "TCP-BASED TABLES".
<b>CASE FOLDING</b>
The search string is folded to lowercase before database lookup. As of
Postfix 2.3, the search string is not case folded with database types
such as <a href="regexp_table.5.html">regexp</a>: or <a href="pcre_table.5.html">pcre</a>: whose lookup fields can match both upper and
lower case.
<b>TABLE FORMAT</b>
The input format for the <a href="postmap.1.html"><b>postmap</b>(1)</a> command is as follows:
<i>pattern result</i>
When <i>pattern</i> matches a mail address, replace it by the corre-
sponding <i>result</i>.
blank lines and comments
Empty lines and whitespace-only lines are ignored, as are lines
whose first non-whitespace character is a `#'.
multi-line text
A logical line starts with non-whitespace text. A line that
starts with whitespace continues a logical line.
<b>TABLE SEARCH ORDER</b>
With lookups from indexed files such as DB or DBM, or from networked
tables such as NIS, LDAP or SQL, patterns are tried in the order as
listed below:
<i>user</i>@<i>domain address</i>
Replace <i>user</i>@<i>domain</i> by <i>address</i>. This form has the highest prece-
dence.
<i>user address</i>
Replace <i>user</i>@<i>site</i> by <i>address</i> when <i>site</i> is equal to $<b><a href="postconf.5.html#myorigin">myorigin</a></b>,
when <i>site</i> is listed in $<b><a href="postconf.5.html#mydestination">mydestination</a></b>, or when it is listed in
$<b><a href="postconf.5.html#inet_interfaces">inet_interfaces</a></b> or $<b><a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a></b>.
@<i>domain address</i>
Replace other addresses in <i>domain</i> by <i>address</i>. This form has the
lowest precedence.
<b>RESULT ADDRESS REWRITING</b>
The lookup result is subject to address rewriting:
<b>o</b> When the result has the form @<i>otherdomain</i>, the result becomes
the same <i>user</i> in <i>otherdomain</i>.
<b>o</b> When "<b><a href="postconf.5.html#append_at_myorigin">append_at_myorigin</a>=yes</b>", append "<b>@$<a href="postconf.5.html#myorigin">myorigin</a></b>" to addresses
without "@domain".
<b>o</b> When "<b><a href="postconf.5.html#append_dot_mydomain">append_dot_mydomain</a>=yes</b>", append "<b>.$<a href="postconf.5.html#mydomain">mydomain</a></b>" to addresses
without ".domain".
<b>ADDRESS EXTENSION</b>
When a mail address localpart contains the optional recipient delimiter
(e.g., <i>user+foo</i>@<i>domain</i>), the lookup order becomes: <i>user+foo</i>@<i>domain</i>,
<i>user</i>@<i>domain</i>, <i>user+foo</i>, <i>user</i>, and @<i>domain</i>.
The <b><a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a></b> parameter controls whether an
unmatched address extension (<i>+foo</i>) is propagated to the result of table
lookup.
<b>REGULAR EXPRESSION TABLES</b>
This section describes how the table lookups change when the table is
given in the form of regular expressions. For a description of regular
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>.
Each pattern is a regular expression that is applied to the entire
address being looked up. Thus, <i>user@domain</i> mail addresses are not bro-
ken up into their <i>user</i> and <i>@domain</i> constituent parts, nor is <i>user+foo</i>
broken up into <i>user</i> and <i>foo</i>.
Patterns are applied in the order as specified in the table, until a
pattern is found that matches the search string.
Results are the same as with indexed file lookups, with the additional
feature that parenthesized substrings from the pattern can be interpo-
lated as <b>$1</b>, <b>$2</b> and so on.
<b>TCP-BASED TABLES</b>
This section describes how the table lookups change when lookups are
directed to a TCP-based server. For a description of the TCP
client/server lookup protocol, see <a href="tcp_table.5.html"><b>tcp_table</b>(5)</a>. This feature is not
available up to and including Postfix version 2.4.
Each lookup operation uses the entire address once. Thus, <i>user@domain</i>
mail addresses are not broken up into their <i>user</i> and <i>@domain</i> con-
stituent parts, nor is <i>user+foo</i> broken up into <i>user</i> and <i>foo</i>.
Results are the same as with indexed file lookups.
<b>EXAMPLE</b>
The following shows a generic mapping with an indexed file. When mail
is sent to a remote host via SMTP, this replaces <i>his@localdomain.local</i>
by his ISP mail address, replaces <i>her@localdomain.local</i> by her ISP mail
address, and replaces other local addresses by his ISP account, with an
address extension of <i>+local</i> (this example assumes that the ISP supports
"+" style address extensions).
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
<a href="postconf.5.html#smtp_generic_maps">smtp_generic_maps</a> = <a href="DATABASE_README.html#types">hash</a>:/etc/postfix/generic
/etc/postfix/generic:
his@localdomain.local hisaccount@hisisp.example
her@localdomain.local heraccount@herisp.example
@localdomain.local hisaccount+local@hisisp.example
Execute the command "<b>postmap /etc/postfix/generic</b>" whenever the table
is changed. Instead of <b>hash</b>, some systems use <b>dbm</b> database files. To
find out what tables your system supports use the command "<b>postconf</b>
<b>-m</b>".
<b>BUGS</b>
The table format does not understand quoting conventions.
<b>CONFIGURATION PARAMETERS</b>
The following <a href="postconf.5.html"><b>main.cf</b></a> parameters are especially relevant. The text
below provides only a parameter summary. See <a href="postconf.5.html"><b>postconf</b>(5)</a> for more
details including examples.
<b><a href="postconf.5.html#smtp_generic_maps">smtp_generic_maps</a></b>
Address mapping lookup table for envelope and header sender and
recipient addresses while delivering mail via SMTP.
<b><a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a></b>
A list of address rewriting or forwarding mechanisms that propa-
gate an address extension from the original address to the
result. Specify zero or more of <b>canonical</b>, <b>virtual</b>, <b>alias</b>, <b>for-</b>
<b>ward</b>, <b>include</b>, or <b>generic</b>.
Other parameters of interest:
<b><a href="postconf.5.html#inet_interfaces">inet_interfaces</a></b>
The network interface addresses that this system receives mail
on. You need to stop and start Postfix when this parameter
changes.
<b><a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a></b>
Other interfaces that this machine receives mail on by way of a
proxy agent or network address translator.
<b><a href="postconf.5.html#mydestination">mydestination</a></b>
List of domains that this mail system considers local.
<b><a href="postconf.5.html#myorigin">myorigin</a></b>
The domain that is appended to locally-posted mail.
<b><a href="postconf.5.html#owner_request_special">owner_request_special</a></b>
Give special treatment to <b>owner-</b><i>xxx</i> and <i>xxx</i><b>-request</b> addresses.
<b>SEE ALSO</b>
<a href="postmap.1.html">postmap(1)</a>, Postfix lookup table manager
<a href="postconf.5.html">postconf(5)</a>, configuration parameters
<a href="smtp.8.html">smtp(8)</a>, Postfix SMTP client
<b>README FILES</b>
<a href="ADDRESS_REWRITING_README.html">ADDRESS_REWRITING_README</a>, address rewriting guide
<a href="DATABASE_README.html">DATABASE_README</a>, Postfix lookup table overview
<a href="STANDARD_CONFIGURATION_README.html">STANDARD_CONFIGURATION_README</a>, configuration examples
<b>LICENSE</b>
The Secure Mailer license must be distributed with this software.
<b>HISTORY</b>
A genericstable feature appears in the Sendmail MTA.
This feature is available in Postfix 2.2 and later.
<b>AUTHOR(S)</b>
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA
GENERIC(5)
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