We have 2 lists at UKCC which have become far too busy and generate
thousands of mail pieces per day. I want to find out 3 things
 
1. Is it possible to set an 'expiration' date to the subscription? If so
how do I do it? Does the subscriber get notified to resubscribe? I think many
of the subscribers got in for curiosity and do not know how to get out, or
do not know that they must unsubscribe.
2. Would any one want to peer any of these two lists? What do I need to do
to set up peer lists?
3. How do I decide which subscribers to pass to the peered list?