NetBSD/gnu/dist/postfix/html/transport.5.html
2002-12-24 19:39:42 +00:00

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TRANSPORT(5) TRANSPORT(5)
<b>NAME</b>
transport - format of Postfix transport table
<b>SYNOPSIS</b>
<b>postmap</b> <b>/etc/postfix/transport</b>
<b>postmap</b> <b>-q</b> <b>"</b><i>string</i><b>"</b> <b>/etc/postfix/transport</b>
<b>postmap</b> <b>-q</b> <b>-</b> <b>/etc/postfix/transport</b> &lt;<i>inputfile</i>
<b>DESCRIPTION</b>
The optional <b>transport</b> table specifies a mapping from
email addresses to message delivery transports and/or
relay hosts. The mapping is used by the <a href="trivial-rewrite.8.html"><b>trivial-rewrite</b>(8)</a>
daemon.
Normally, the <b>transport</b> 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</b> <b>/etc/postfix/transport</b> in order to rebuild the
indexed file after changing the transport table.
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 expres-
sions. In that case, the lookups are done in a slightly
different way as described in section "REGULAR EXPRESSION
TABLES".
<b>TABLE</b> <b>FORMAT</b>
The format of the transport table is as follows:
<i>pattern</i> <i>result</i>
When <i>pattern</i> matches the recipient address or
domain, use the corresponding <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 logi-
cal line.
The <i>pattern</i> specifies an email address, a domain name, or
a domain name hierarchy, as described in section "TABLE
LOOKUP".
The <i>result</i> is of the form <i>transport</i><b>:</b><i>nexthop</i>. The <i>trans-</i>
<i>port</i> field specifies a mail delivery transport such as
<b>smtp</b> or <b>local</b>. The <i>nexthop</i> field specifies where and how
to deliver mail. More details are given in section "RESULT
FORMAT".
<b>TABLE</b> <b>LOOKUP</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+extension@domain</i> <i>transport</i>:<i>nexthop</i>
Mail for <i>user+extension@domain</i> is delivered through
<i>transport</i> to <i>nexthop</i>.
<i>user@domain</i> <i>transport</i>:<i>nexthop</i>
Mail for <i>user@domain</i> is delivered through <i>transport</i>
to <i>nexthop</i>.
<i>domain</i> <i>transport</i>:<i>nexthop</i>
Mail for <i>domain</i> is delivered through <i>transport</i> to
<i>nexthop</i>.
<i>.domain</i> <i>transport</i>:<i>nexthop</i>
Mail for any subdomain of <i>domain</i> is delivered
through <i>transport</i> to <i>nexthop</i>. This applies only
when the string <b>transport</b><i>_</i><b>maps</b> is not listed in the
<b>parent</b><i>_</i><b>domain</b><i>_</i><b>matches</b><i>_</i><b>subdomains</b> configuration set-
ting. Otherwise, a domain name matches itself and
its subdomains.
Note 1: the special pattern <b>*</b> represents any address (i.e.
it functions as the wild-card pattern).
Note 2: the null recipient address is looked up as
<b>$empty</b><i>_</i><b>address</b><i>_</i><b>recipient</b>@<b>$myhostname</b> (default: mailer-dae-
mon@hostname).
<b>RESULT</b> <b>FORMAT</b>
The transport field specifies the name of a mail delivery
transport (the first name of a mail delivery service entry
in the Postfix <b>master.cf</b> file).
The interpretation of the nexthop field is transport
dependent. In the case of SMTP, specify <i>host</i>:<i>service</i> for a
non-default server port, and use [<i>host</i>] or [<i>host</i>]:<i>port</i> in
order to disable MX (mail exchanger) DNS lookups. The []
form can also be used with IP addresses instead of host-
names.
A null <i>transport</i> and null <i>nexthop</i> result means "do not
change": use the delivery transport and nexthop informa-
tion that would be used when the entire transport table
did not exist.
A non-null <i>transport</i> field with a null <i>nexthop</i> field
resets the nexthop information to the recipient domain.
A null <i>transport</i> field with non-null <i>nexthop</i> field does
not modify the transport information.
<b>EXAMPLES</b>
In order to deliver internal mail directly, while using a
mail relay for all other mail, specify a null entry for
internal destinations (do not change the delivery trans-
port or the nexthop information) and specify a wildcard
for all other destinations.
<b>my.domain</b> <b>:</b>
<b>.my.domain</b> <b>:</b>
<b>*</b> <b>smtp:outbound-relay.my.domain</b>
In order to send mail for <b>foo.org</b> and its subdomains via
the <b>uucp</b> transport to the UUCP host named <b>foo</b>:
<b>foo.org</b> <b>uucp:foo</b>
<b>.foo.org</b> <b>uucp:foo</b>
When no nexthop host name is specified, the destination
domain name is used instead. For example, the following
directs mail for <i>user</i>@<b>foo.org</b> via the <b>slow</b> transport to a
mail exchanger for <b>foo.org</b>. The <b>slow</b> transport could be
something that runs at most one delivery process at a
time:
<b>foo.org</b> <b>slow:</b>
When no transport is specified, Postfix uses the transport
that matches the address domain class (see TRANSPORT FIELD
discussion above). The following sends all mail for
<b>foo.org</b> and its subdomains to host <b>gateway.foo.org</b>:
<b>foo.org</b> <b>:[gateway.foo.org]</b>
<b>.foo.org</b> <b>:[gateway.foo.org]</b>
In the above example, the [] are used to suppress MX
lookups. The result would likely point to your local
machine.
In the case of delivery via SMTP, one may specify <i>host-</i>
<i>name</i>:<i>service</i> instead of just a host:
<b>foo.org</b> <b>smtp:bar.org:2025</b>
This directs mail for <i>user</i>@<b>foo.org</b> to host <b>bar.org</b> port
<b>2025</b>. Instead of a numerical port a symbolic name may be
used. Specify [] around the hostname in order to disable
MX lookups.
The error mailer can be used to bounce mail:
<b>.foo.org</b> <b>error:mail</b> <b>for</b> <b>*.foo.org</b> <b>is</b> <b>not</b> <b>deliv-</b>
<b>erable</b>
This causes all mail for <i>user</i>@<i>anything</i><b>.foo.org</b> to be
bounced.
<b>REGULAR</b> <b>EXPRESSION</b> <b>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</b><i>_</i><b>table</b>(5)</a> or <a href="pcre_table.5.html"><b>pcre</b><i>_</i><b>table</b>(5)</a>.
Each pattern is a regular expression that is applied to
the entire domain being looked up. Thus, <i>some.domain.hier-</i>
<i>archy</i> is not broken up into parent domains.
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 interpolated as <b>$1</b>, <b>$2</b> and so on.
<b>CONFIGURATION</b> <b>PARAMETERS</b>
The following <b>main.cf</b> parameters are especially relevant
to this topic. See the Postfix <b>main.cf</b> file for syntax
details and for default values. Use the <b>postfix</b> <b>reload</b>
command after a configuration change.
<b>empty</b><i>_</i><b>address</b><i>_</i><b>recipient</b>
The address that is looked up instead of the null
sender address.
<b>parent</b><i>_</i><b>domain</b><i>_</i><b>matches</b><i>_</i><b>subdomains</b>
List of Postfix features that use <i>domain.tld</i> pat-
terns to match <i>sub.domain.tld</i> (as opposed to
requiring <i>.domain.tld</i> patterns).
<b>transport</b><i>_</i><b>maps</b>
List of transport lookup tables.
<b>SEE</b> <b>ALSO</b>
<a href="postmap.1.html">postmap(1)</a> create mapping table
<a href="trivial-rewrite.8.html">trivial-rewrite(8)</a> rewrite and resolve addresses
<a href="pcre_table.5.html">pcre_table(5)</a> format of PCRE tables
<a href="regexp_table.5.html">regexp_table(5)</a> format of POSIX regular expression tables
<b>LICENSE</b>
The Secure Mailer license must be distributed with this
software.
<b>AUTHOR(S)</b>
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
TRANSPORT(5)
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