110 Can’t open SMTP stream

I found the config for cpanel’s SM:

/usr/local/cpanel/base/3rdparty/squirrelmail/config/config.php

I just changed:
$useSendmail = false;

to:
$useSendmail = true;

(around line 33)

This will probably get written over with the next cpanel update, but it at least helps get my users sending mail again for