How to bind your Qmail server to a specific IP address

Just a little tip :

By default, Qmail listens to all the available IP address on the machine (0.0.0.0). It is possible to change this behaviour to bind Qmail to a specific IP.

We suppose that you are using Qmail from Dotdeb and launching it using the provided init script, /etc/init.d/qmail. Just edit it and change these lines :

          sh -c "start-stop-daemon --start --quiet --user qmaild \
          --pidfile /var/run/tcpserver_smtpd.pid --make-pidfile \
          --exec /usr/bin/tcpserver -- -H -P -R -l 0 \
          -u `id -u qmaild` -g `id -g nobody` -x /etc/tcp.smtp.cdb 0 smtp \
          $rblsmtpd /usr/sbin/qmail-smtpd 2>&1 \
          | $logger &"

by those ones :

          sh -c "start-stop-daemon --start --quiet --user qmaild \
          --pidfile /var/run/tcpserver_smtpd.pid --make-pidfile \
          --exec /usr/bin/tcpserver -- -H -P -R -l 0 \
          -u `id -u qmaild` -g `id -g nobody` -x /etc/tcp.smtp.cdb xxx.xxx.xxx.xxx smtp \
          $rblsmtpd /usr/sbin/qmail-smtpd 2>&1 \
          | $logger &"

(Just replace xxx.xxx.xxx.xxx by your IP address)

Now, when you list your listening dameon, you should see tcpserver listening to xxx.xxx.xxx.xxx:25 instead of 0.0.0.0:25.

machine# netstat -apn
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 xxx.xxx.xxx.xxx:25      0.0.0.0:*               LISTEN      21175/tcpserver