Qmail : How to change the default submission SMTP port

By default, the submission port is TCP-587. To change to another value, edit the following file :

/var/qmail/supervise/submission/run

1	/var/qmail/supervise/submission/run

And simply change the port number just before the last line :

/usr/bin/tcpserver -v -R -H -l $HOSTNAME -x $TCP_CDB -c "$MAXSMTPD" \
-u "$QMAILDUID" -g "$NOFILESGID" 0 587 \
$SMTPD $VCHKPW /bin/true 2>&1

/usr/bin/tcpserver -v -R -H -l $HOSTNAME -x $TCP_CDB -c "$MAXSMTPD" \

-u "$QMAILDUID" -g "$NOFILESGID" 0 587 \

$SMTPD $VCHKPW /bin/true 2>&1

Of course, you need to restart qmail to make it effective.