Provided by: postfix_3.6.4-1ubuntu2_amd64 bug


       transport - Postfix transport table format


       postmap /etc/postfix/transport

       postmap -q "string" /etc/postfix/transport

       postmap -q - /etc/postfix/transport <inputfile


       The  optional  transport(5)  table  specifies  a  mapping  from email addresses to message
       delivery transports and next-hop destinations.  Message delivery transports such as  local
       or  smtp  are defined in the file, and next-hop destinations are typically hosts
       or domain names. The table is searched by the trivial-rewrite(8) daemon.

       This mapping overrides the default transport:nexthop selection that is built into Postfix:

       local_transport (default: local:$myhostname)
              This is the default for final delivery to domains listed  with  mydestination,  and
              for  [ipaddress] destinations that match $inet_interfaces or $proxy_interfaces. The
              default nexthop destination is the MTA hostname.

       virtual_transport (default: virtual:)
              This   is   the   default   for   final   delivery   to   domains    listed    with
              virtual_mailbox_domains. The default nexthop destination is the recipient domain.

       relay_transport (default: relay:)
              This  is  the  default for remote delivery to domains listed with relay_domains. In
              order  of  decreasing  precedence,  the   nexthop   destination   is   taken   from
              relay_transport,  sender_dependent_relayhost_maps, relayhost, or from the recipient

       default_transport (default: smtp:)
              This is the default for  remote  delivery  to  other  destinations.   In  order  of
              decreasing     precedence,     the    nexthop    destination    is    taken    from
              sender_dependent_default_transport_maps,                         default_transport,
              sender_dependent_relayhost_maps, relayhost, or from the recipient domain.

       Normally,  the  transport(5) 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" to
       rebuild an indexed file after changing the corresponding 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, 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


       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 regexp: or pcre: whose lookup
       fields can match both upper and lower case.


       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 SEARCH ORDER".

       The  result  is  of the form transport:nexthop and specifies how or where to deliver mail.
       This is described in section "RESULT FORMAT".


       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
              Deliver mail for user+extension@domain through transport to nexthop.

       user@domain transport:nexthop
              Deliver mail for user@domain through transport to nexthop.

       domain transport:nexthop
              Deliver mail for domain through transport to nexthop.

       .domain transport:nexthop
              Deliver mail for any subdomain of domain 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 subdomains.

       * transport:nexthop
              The special pattern * represents any address (i.e. it functions  as  the  wild-card
              pattern, and is unique to Postfix transport tables).

       Note  1:  the  null recipient address is looked up as $empty_address_recipient@$myhostname
       (default: mailer-daemon@hostname).

       Note 2: user@domain or user+extension@domain lookup is available in Postfix 2.0 and later.


       The lookup result is of the form transport:nexthop.  The transport field specifies a  mail
       delivery  transport  such  as  smtp or local. The nexthop field specifies where and how to
       deliver mail.

       The transport field specifies the name of a mail delivery transport (the first name  of  a
       mail delivery service entry in the Postfix file).

       The  nexthop  field usually specifies one recipient domain or hostname. In the case of the
       Postfix SMTP/LMTP client, the nexthop field may contain a  list  of  nexthop  destinations
       separated by comma or whitespace (Postfix 3.5 and later).

       The  syntax of a nexthop destination is transport dependent.  With SMTP, specify a service
       on a non-default port as host:service, and disable MX (mail exchanger)  DNS  lookups  with
       [host] or [host]:port. The [] form is required when you specify an IP address instead of a

       A null transport and null nexthop field 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


       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 specify a wildcard for all other destinations.

            my.domain    :
            .my.domain   :

       In  order  to  send  mail for and its subdomains via the uucp transport to the
       UUCP host named example:


       When no nexthop host name is specified, the destination domain name is used  instead.  For
       example,  the following directs mail for via the slow transport to a mail
       exchanger for  The slow transport could be configured  to  run  at  most  one
       delivery process at a time:


       When no transport is specified, Postfix uses the transport that matches the address domain
       class (see DESCRIPTION above).  The following sends  all  mail  for  and  its
       subdomains to host


       In  the  above example, the [] suppress MX lookups.  This prevents mail routing loops when
       your machine is primary MX host for

       In the case of delivery via SMTP or LMTP, one may specify host:service instead of  just  a


       This  directs  mail  for  to  host  bar.example  port 2025. Instead of a
       numerical port a symbolic name may be used. Specify [] around the hostname if  MX  lookups
       must be disabled.

       Deliveries via SMTP or LMTP support multiple destinations (Postfix >= 3.5):

        smtp:bar.example, foo.example

       This tries to deliver to bar.example before trying to deliver to foo.example.

       The error mailer can be used to bounce mail:

       error:mail for * is not deliverable

       This causes all mail for to be bounced.


       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 address being looked
       up. Thus,  some.domain.hierarchy  is  not  looked  up  via  its  parent  domains,  nor  is
       user+foo@domain looked up as user@domain.

       Patterns are applied in the order as specified in the table, until a pattern is found that
       matches the search string.

       The trivial-rewrite(8) server disallows regular expression  substitution  of  $1  etc.  in
       regular expression lookup tables, because that could open a security hole (Postfix version
       2.3 and later).


       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
       tcp_table(5).  This feature is not available up to and including Postfix version 2.4.

       Each lookup operation uses the entire recipient address once.  Thus, some.domain.hierarchy
       is not looked up via its parent domains, nor is user+foo@domain looked up as user@domain.

       Results are the same as with indexed file lookups.


       The  following parameters are especially relevant.  The text below provides only a
       parameter summary. See postconf(5) for more details including examples.

       empty_address_recipient (MAILER-DAEMON)
              The recipient of mail addressed to the null address.

       parent_domain_matches_subdomains (see 'postconf -d' output)
              A list of Postfix features where the pattern "" also matches  subdomains
              of, instead of requiring an explicit "" pattern.

       transport_maps (empty)
              Optional  lookup  tables  with mappings from recipient address to (message delivery
              transport, next-hop destination).


       trivial-rewrite(8), rewrite and resolve addresses
       master(5), file format
       postconf(5), configuration parameters
       postmap(1), Postfix lookup table manager


       Use "postconf readme_directory" or "postconf html_directory" to locate this information.
       ADDRESS_REWRITING_README, address rewriting guide
       DATABASE_README, Postfix lookup table overview
       FILTER_README, external content filter


       The Secure Mailer license must be distributed with this software.


       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