Index: common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.624
diff -u -r1.624 common.inc
--- common.inc	27 Mar 2007 05:13:53 -0000	1.624
+++ common.inc	28 Mar 2007 01:02:59 -0000
@@ -1975,10 +1975,10 @@
   $message = array('#mail_id' => $mailkey, '#to' => $to, '#subject' => $subject, '#body' => $body, '#from' => $from, '#headers' => $headers);
   drupal_alter('mail', $message);
   $mailkey = $message['#mail_id'];
-  $to = $message['#to'];
+  $to = strtolower($message['#to']);
   $subject = $message['#subject'];
   $body = $message['#body'];
-  $from = $message['#from'];
+  $from = strtolower($message['#from']);
   $headers = $message['#headers'];
 
   // Allow for custom mail backend