[bug-mailutils] Maidag + LMTP

[Sergey Poznyakoff]

Hi Chris,

To run maidag as a LMTP daemon you will need to put the following in its
configuration file:

# Run in daemon mode.
mode daemon;
# Force LMTP
delivery-mode lmtp;
# Listen on 127.0.0.1 port 2525. Of course you can select any other
# IP/port here.
server localhost:2525 {
  # Some settings here. See maidag --config-help for details.
  # Currently at least one keyword must be present. 
  transcript no;
  # When listening on an IP other than loopback, the "acl" section will
  # be useful, e.g.:
  # acl {
  #    allow from X.X.X.X/Y;
  #    deny from any;
  # }
}

Basically, that's all.  To listen on a UNIX socket instead of the
network interface, use:

server socket:///path/to/socket {...

If Mailutils was configured with support for TCP wrappers, you might
also need to configure the tcp-wrappers section.  By default maidag
will consider "maidag" entries in /etc/hosts.allow, /etc/hosts.deny.
Normally you would put

maidag: 127.0.0.1

in your /etc/hosts.allow.  The tcp-wrappers section offers a
fine-grained control over this.  For example, to use another daemon
name:

tcp-wrappers {
  daemon "lmtp";
}

(then the entries in /etc/hosts.* would look like:

  lmtp: X.X.X.X ...

)

To disable tcp wrappers:

tcp-wrappers {
  enable no;
}

There are still more settings in this section.  As usual, "maidag
--config-help" is your friend:) 

A number of settings is provided that control the daemon behavior:

1. Normally maidag changes to group "mail" after startup. To change this
use the group statement, e.g.:

  group (mail,lmtp);

2. To control the maximum number of subprocesses (i.e. the number of
simultaneous LMTP connections): 

   max-children N;

where N is a decimal number.

3. To set idle timeout for a session:

   timeout SECONDS;

4. To store PID of the master process in a file:

   pidfile "/path/to/file";

If you prefer to run maidag from inetd, instead of running it as a
daemon, then use this:

   mode inetd;
   delivery-mode lmtp;

However, daemon mode is much more flexible, so I'd suggest using it.

You can also configure a "forward-file" functionality, similar to that
of Sendmail or Exim, e.g.:

   forward-file ".forward";

Before reading that file, maidag applies a number of safety checks to it
and refuses to rely on it if it does not pass them. These checks are
described in detail here:

   http://mailutils.org/wiki/File_Safety_Checks#The_Forward_File


Regards,
Sergey