diff -Naur phpmailer/includes/phpmailer.drupal.inc /ligo/www/edupal/6x/sites/all/modules/phpmailer/includes/phpmailer.drupal.inc
--- phpmailer/includes/phpmailer.drupal.inc	2009-01-19 17:08:17.000000000 +0100
+++ /ligo/www/edupal/6x/sites/all/modules/phpmailer/includes/phpmailer.drupal.inc	2009-02-19 02:16:41.000000000 +0100
@@ -111,6 +111,15 @@
   if ($mail->SMTPKeepAlive) {
     $mail->Reset();
   }
+  else {
+    /* class PHPMailer has no proper constructor or destructor;
+     * so DrupalPHPMailer can't call any destructor. Furthermore, $mail
+     * is static, whatever the implications for its lifetime.
+     * Not calling Reset() at this point could and did cause unwanted 
+     * distribution of mails to multiple To: recipients. -ungeek-
+    */
+    $mail->Reset();
+  }
 
   if ($mail->SMTPDebug) {
     if ($debug = ob_get_contents()) {