Just a note to inform you of a small issue in ListMessenger Pro 2.2 Build 20081125 on a very few number of installations.
If you use PHP's mail() function to send mail and get a message when trying to send newsletters that states "Could not instantiate mail function." and you *do* have PHP's mail() function configured correctly on your server:
PHPMailer checks to see if safe_mode is configured or not if you use PHP's mail() function. If safe_mode is disabled then it attempts to set the 5th parameter of the mail() function, which is a "fail safe" method of setting the Return-Path (bounce back e-mail address). The problem is when your server (despite having safe_mode disabled) does not allow PHP to set this parameter. In the next build of ListMessenger 2.2 I have added two mail() function sending options [basic] and [advanced] to resolve this issue.
If you would like to resolve this issue immediately simply download the attached phpmailer.class.php file and place it in your listmessenger/includes/classes/phpmailer directory.
Warning: This file is for ListMessenger Light & Pro 2.2 Build 20081125 Only.