Message-ID not set correctly

The mail2web module sets the Header-ID of the email message. In PHPMailer there is a special call for this property. Just do:

case 'message-id':
$mail->MessageID = $value;
break;

//and continue with the rest of the headers:
default:
// The header key is not special - add it as is.
$mail->AddCustomHeader($key .': '. $value);

<./code>

(this issue was also solved in the messaging_phpmailer module:

http://drupal.org/node/363001#new )