We are still in mixed-mode with Exchange 5.5. We cannot get the DST patch. Will the manual patch be enough?

Q: We are still in mixed-mode with Exchange 5.5.  We cannot get the DST patch.  Will the manual patch be enough?  We don't have any mailboxes on Exchange 5.5, it only routes.
A: If users are not connecting to this box using CDO (like OWA users) then you don't need the CDO update.  You should still look at the guidance in http://support.microsoft.com/kb/914387 regarding the OS.