We were abe to get this worked out by adding in the additional "-f" parameter into the php mail call that is located in the WA_UniversalEmal > mail_PHP.php file near line 254. Here is what the updated line looks like:
$mailObj = mail($mailTo,$mailSubject,$mailContent,$mailHeader, "-f" . $mailFrom);
This additional -f parameter is used by some host to ensure that the sender is allowed on the server.