Index: wp-includes/pluggable-functions.php
===================================================================
--- wp-includes/pluggable-functions.php	(revision 3000)
+++ wp-includes/pluggable-functions.php	(working copy)
@@ -278,7 +278,7 @@
 	$notify_message .= sprintf( __('To delete this comment, visit: %s'), get_settings('siteurl').'/wp-admin/post.php?action=confirmdeletecomment&p='.$comment->comment_post_ID."&comment=$comment_id" ) . "\r\n";
 
 	if ('' == $comment->comment_author_email || '' == $comment->comment_author) {
-		$from = "From: \"$blogname\" <wordpress@" . $_SERVER['SERVER_NAME'] . '>';
+		$from = "From: \"$blogname\" <wordpress@" . preg_replace("/^www\./", "", $_SERVER['SERVER_NAME']) . '>';
 	} else {
 		$from = 'From: "' . $comment->comment_author . "\" <$comment->comment_author_email>";
 	}