Provided by: postfix_2.8.5-2~build1_i386 bug

NAME

       transport - Postfix transport table format

SYNOPSIS

       postmap /etc/postfix/transport

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

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

DESCRIPTION

       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
       master.cf 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 domain.

       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 EXPRESSION
       TABLES" or "TCP-BASED TABLES".

CASE FOLDING

       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.

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 and specifies how or where
       to deliver mail. This is described in section "RESULT FORMAT".

TABLE SEARCH ORDER

       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.

RESULT FORMAT

       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
       master.cf file).

       The  interpretation of the nexthop field is transport dependent. In the
       case of 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
       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
       specify a wildcard for all other destinations.

            my.domain    :
            .my.domain   :
            *            smtp:outbound-relay.my.domain

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

            example.com      uucp:example
            .example.com     uucp:example

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

            example.com      slow:

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

            example.com      :[gateway.example.com]
            .example.com     :[gateway.example.com]

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

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

            example.com      smtp:bar.example:2025

       This directs mail for user@example.com 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.

       The error mailer can be used to bounce mail:

            .example.com     error:mail for *.example.com is not deliverable

       This causes all mail for user@anything.example.com 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
       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).

TCP-BASED TABLES

       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.

CONFIGURATION PARAMETERS

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

       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

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

README FILES

       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

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)