Index: wp-includes/pluggable.php
===================================================================
--- wp-includes/pluggable.php	(revision 6559)
+++ wp-includes/pluggable.php	(working copy)
@@ -238,7 +238,6 @@
 
 	// Set the from name and email
 	$phpmailer->From = apply_filters( 'wp_mail_from', $from_email );
-	$phpmailer->Sender = apply_filters( 'wp_mail_from', $from_email );
 	$phpmailer->FromName = apply_filters( 'wp_mail_from_name', $from_name );
 
 	// Set destination address