# TRANSPORT(5)                                                      TRANSPORT(5)
# 
# NAME
#        transport - format of Postfix transport table
# 
# SYNOPSIS
#        postmap /etc/postfix/transport
# 
#        postmap -q "string" /etc/postfix/transport
# 
#        postmap -q - /etc/postfix/transport <inputfile
# 
# DESCRIPTION
#        The  optional  transport table specifies a mapping from email addresses
#        to message delivery transports and/or relay hosts. The mapping is  used
#        by the trivial-rewrite(8) daemon.
# 
#        This mapping overrides the default routing that is built into Postfix:
# 
#        mydestination
#               A list of domains that is by default delivered via $local_trans-
#               port.
# 
#        virtual_mailbox_domains
#               A list of  domains  that  is  by  default  delivered  via  $vir-
#               tual_transport.
# 
#        relay_domains
#               A list of domains that is by default delivered via $relay_trans-
#               port.
# 
#        any other destination
#               Mail for any other  destination  is  by  default  delivered  via
#               $default_transport.
# 
#        Normally,  the  transport table is specified as a text file that 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. Execute
#        the command postmap /etc/postfix/transport  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 expressions. In that case, the
#        lookups are done in a slightly different way as  described  in  section
#        "REGULAR EXPRESSION TABLES".
# 
# TABLE FORMAT
#        The input format for the postmap(1) command is as follows:
# 
#        pattern result
#               When  pattern  matches  the recipient address or domain, use the
#               corresponding result.
# 
#        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.
# 
#        The pattern specifies an email address, a domain name, or a domain name
#        hierarchy, as described in section "TABLE LOOKUP".
# 
#        The result is of the form transport:nexthop.  The transport field spec-
#        ifies a mail delivery transport such as  smtp  or  local.  The  nexthop
#        field  specifies  where and how to deliver mail. More details are given
#        in section "RESULT FORMAT".
# 
# TABLE LOOKUP
#        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:
# 
#        user+extension@domain transport:nexthop
#               Mail for user+extension@domain is delivered through transport to
#               nexthop.
# 
#        user@domain transport:nexthop
#               Mail  for user@domain is delivered through transport to nexthop.
# 
#        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. This applies only when the string transport_maps is
#               not listed in the parent_domain_matches_subdomains configuration
#               setting.  Otherwise, a domain name matches itself and its subdo-
#               mains.
# 
#        Note 1: the special pattern * represents any address (i.e. it functions
#        as the wild-card pattern).
# 
#        Note    2:    the    null   recipient   address   is   looked   up   as
#        $empty_address_recipient@$myhostname (default: mailer-daemon@hostname).
# 
# RESULT FORMAT
#        The  transport  field  specifies  the name of a mail delivery transport
#        (the first name of a mail delivery service entry in  the  Postfix  mas-
#        ter.cf file).
# 
#        The  interpretation of the nexthop field is transport 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 is required when you specify an IP address instead
#        of a hostname.
# 
#        A null transport and null nexthop result means "do not change": use the
#        delivery transport and nexthop information that would be used when  the
#        entire transport table did not exist.
# 
#        A non-null transport field with a null nexthop field resets the nexthop
#        information to the recipient domain.
# 
#        A null transport field with non-null nexthop field does not modify  the
#        transport information.
# 
# EXAMPLES
#        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 transport or the nexthop information) and spec-
#        ify a wildcard for all other destinations.
# 
#             my.domain    :
#             .my.domain   :
#             *            smtp:outbound-relay.my.domain
# 
#        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:
# 
#        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 foo.org and its subdomains to host gate-
#        way.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
#        hostname 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@anything.foo.org to be bounced.
# 
# REGULAR EXPRESSION TABLES
#        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 regexp_table(5) or pcre_table(5).
# 
#        Each pattern is a regular expression that  is  applied  to  the  entire
#        domain  being  looked  up. Thus, some.domain.hierarchy 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  interpo-
#        lated as $1, $2 and so on.
# 
# 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.
# 
#        empty_address_recipient
#               The  address  that  is  looked  up  instead  of  the null sender
#               address.
# 
#        parent_domain_matches_subdomains
#               List of Postfix features that use domain.tld patterns  to  match
#               sub.domain.tld (as opposed to requiring .domain.tld patterns).
# 
#        transport_maps
#               List of transport lookup tables.
# 
# SEE ALSO
#        postmap(1) create mapping table
#        trivial-rewrite(8) rewrite and resolve addresses
#        pcre_table(5) format of PCRE tables
#        regexp_table(5) format of POSIX regular expression tables
# 
# LICENSE
#        The Secure Mailer license must be distributed with this software.
# 
# AUTHOR(S)
#        Wietse Venema
#        IBM T.J. Watson Research
#        P.O. Box 704
#        Yorktown Heights, NY 10598, USA
# 
#                                                                   TRANSPORT(5)
