Message not Delivered notifications for Agenda emails

Ok, I have modified the unsubscribe/opt-out code so that the unsubscribe links in emails for guests and former members only work so long as that person is still a guest or former member. If they become a member (new or again), then proceed to click an unsubscribe link in an old email to them from when they were a guest or former member, the link will not kill their email address. (as long as they are detected to be a member)