Force SMTP Authentication On A cPanel Server

By default, a cPanel server uses POP before SMTP as its method of checking if a sender is allowed to send mail via the server. However, if you would like to force people to use proper SMTP authentication then there is a simple shell command that will enable this requirement.

To force SMTP authentication on your cPanel server, login to SSH as root and issue the following command:

/usr/local/cpanel/bin/tailwatchd –disable=Cpanel::TailWatch::Antirelayd

If you would like to undo this at any stage, just enter the following:

/usr/local/cpanel/bin/tailwatchd –disable=Cpanel::TailWatch::Antirelayd