Index: messaging_phpmailer/messaging_phpmailer.module
===================================================================
--- messaging_phpmailer/messaging_phpmailer.module	(revision 928)
+++ messaging_phpmailer/messaging_phpmailer.module	(working copy)
@@ -119,7 +119,9 @@
  * to be able to send mail with both PHPMailer and MIMEMail.
  */
 function messaging_phpmailer_drupal_mail($message) {
-  include_once './'. drupal_get_path('module', 'messaging_phpmailer') .'/PHPMailer/class.phpmailer.php';
+  if (!class_exists('PHPMailer')) {
+    include_once './'. drupal_get_path('module', 'messaging_phpmailer') .'/PHPMailer/class.phpmailer.php';
+  }
   $mail = new PHPMailer();
   $mail->IsSMTP(); // telling the class to use SMTP
   $mail->CharSet = 'utf-8';