In the WA_UniversalEmail/mail_PHP.php, find the following line of code:
$lineEnd = "\r\n";
and change it to:
if(isset($_SERVER['SERVER_SOFTWARE']) && stristr($_SERVER['SERVER_SOFTWARE'],'microsoft')){
$lineEnd = "\r\n";
}else{
$lineEnd = "\n";
}
On The download page for Universal Email, see the know issues section for a file to fix this problem.