TRANSPORT(5) TRANSPORT(5)
NAME
transport - format of Postfix transport table
SYNOPSIS
postmap /etc/postfix/transport
DESCRIPTION
The optional transport file specifies a mapping from
domain hierarchies to message delivery transports and/or
relay hosts. The mapping is used by the trivial-rewrite(8)
daemon.
The file serves as input to the postmap(1) command. The
result, an indexed file in dbm or db format, is used for
fast searching by the mail system. After updating this
table, issue the postfix reload command to make the change
visible.
The format of the transport table is as follows:
blanks and comments
Blank lines are ignored, as are lines beginning
with `#'.
domain transport:nexthop
Mail for domain is delivered through transport to
nexthop.
.domain transport:nexthop
Mail for any subdomain of domain is delivered
through transport to nexthop.
The interpretation of the nexthop field is trans-
port dependent. In the case of SMTP, specify
host:service for a non-default server port, and use
[host] or [host:port] in order to disable MX (mail
exchanger) DNS lookups. The [] form can also be
used with IP addresses instead of hostnames.
EXAMPLES
In order to send mail for foo.org and its subdomains
via the uucp transport to the UUCP host named foo:
foo.org uucp:foo
.foo.org uucp:foo
When no nexthop host name is specified, the destination domain
name is used instead. For example, the following directs mail for
user@foo.org via the slow transport to a mail
exchanger for foo.org. The slow transport could be
something that runs at most one delivery process at a time:
foo.org slow:
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When no transport is specified, the default transport is
used, as specified via the default_transport configuration
parameter. The following sends all mail for foo.org and its
subdomains to host gateway.foo.org:
foo.org :[gateway.foo.org]
.foo.org :[gateway.foo.org]
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
hostname:service instead of just a host:
foo.org smtp:bar.org:2025
This directs mail for user@foo.org to host bar.org
port 2025. Instead of a numerical port a symbolic name may be
used. Specify [] around the destination in order to disable MX lookups.
The error mailer can be used to bounce mail:
.foo.org error:mail for *.foo.org is not deliverable
This causes all mail for user@anythingfoo.org
to be bounced.
CONFIGURATION PARAMETERS
The following main.cf parameters are especially relevant
to this topic. See the Postfix main.cf file for syntax
details and for default values. Use the postfix reload
command after a configuration change.
transport_maps
List of transport lookup tables.
Other parameters of interest:
default_transport
The transport to use when no transport is explic-
itly specified.
relayhost
The default host to send to when no transport table
entry matches.
SEE ALSO
postmap(1) create mapping table
trivial-rewrite(8) rewrite and resolve addresses
LICENSE
The Secure Mailer license must be distributed with this
software.
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TRANSPORT(5) TRANSPORT(5)
AUTHOR(S)
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
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