@node Postfix
@unnumbered Integration with Postfix

This section is taken from @url{http://www.postfix.org/nncp_README.html,
Postfix and UUCP} manual and just replaces UUCP-related calls with NNCP
ones.

@strong{Setting up a Postfix Internet to NNCP gateway}

Here is how to set up a machine that sits on the Internet and that forwards
mail to a LAN that is connected via NNCP.

@itemize

@item You need an @ref{nncp-mail} program that extracts the sender
address from mail that arrives via NNCP, and that feeds the mail into
the Postfix @command{sendmail} command.

@item Define a @command{pipe(8)} based mail delivery transport for
delivery via NNCP:
@verbatim
/usr/local/etc/postfix/master.cf:
nncp      unix  -       n       n       -       -       pipe
          flags=F user=nncp argv=nncp-mail -quiet $nexthop $recipient
@end verbatim

This runs the @command{nncp-mail} command to place outgoing mail into
the NNCP queue after replacing @var{$nexthop} by the the receiving NNCP
node and after replacing @var{$recipient} by the recipients. The
@command{pipe(8)} delivery agent executes the @command{nncp-mail}
command without assistance from the shell, so there are no problems with
shell meta characters in command-line parameters.

@item Specify that mail for @emph{example.com}, should be delivered via
NNCP, to a host named @emph{nncp-host}:

@verbatim
/usr/local/etc/postfix/transport:
    example.com     nncp:nncp-host
    .example.com    nncp:nncp-host
@end verbatim

See the @command{transport(5)} manual page for more details.

@item Execute the command @command{postmap /etc/postfix/transport}
whenever you change the @file{transport} file.

@item Enable @file{transport} table lookups:

@verbatim
/usr/local/etc/postfix/main.cf:
    transport_maps = hash:$config_directory/transport
@end verbatim

@item Add @emph{example.com} to the list of domains that your site is
willing to relay mail for.

@verbatim
/usr/local/etc/postfix/main.cf:
    relay_domains = example.com ...other relay domains...
@end verbatim

See the @option{relay_domains} configuration parameter description for
details.

@item Execute the command @command{postfix reload} to make the changes
effective.

@end itemize

@strong{Setting up a Postfix LAN to NNCP gateway}

Here is how to relay mail from a LAN via NNCP to the Internet.

@itemize

@item You need an @ref{nncp-mail} program that extracts the sender
address from mail that arrives via NNCP, and that feeds the mail into
the Postfix @command{sendmail} command.

@item Specify that all remote mail must be sent via the @command{nncp}
mail transport to your NNCP gateway host, say, @emph{nncp-gateway}:

@verbatim
/usr/local/etc/postfix/main.cf:
    relayhost = nncp-gateway
    default_transport = nncp
@end verbatim

Postfix 2.0 and later also allows the following more succinct form:

@verbatim
/usr/local/etc/postfix/main.cf:
    default_transport = nncp:nncp-gateway
@end verbatim

@item Define a @command{pipe(8)} based message delivery transport for
mail delivery via NNCP:

@verbatim
/usr/local/etc/postfix/master.cf:
nncp      unix  -       n       n       -       -       pipe
          flags=F user=nncp argv=nncp-mail -quiet $nexthop $recipient
@end verbatim

This runs the @command{nncp-mail} command to place outgoing mail into
the NNCP queue. It substitutes the hostname (@emph{nncp-gateway}, or
whatever you specified) and the recipients before executing the command.
The @command{nncp-mail} command is executed without assistance from the
shell, so there are no problems with shell meta characters.

@item Execute the command @command{postfix reload} to make the changes
effective.

@end itemize