I use index rather than digest for certain bounces. An index might get
through where the much longer digest does not.  If it bounces, at least
I have saved bandwidth.  If the index does get through, the subscriber then has
to learn how to use the database retrieval system of Listserv---expands them a
bit.
 
"No such user" or "full mailboxes" are unsubscribed immediately.  Rather than
saying AOL should change its policy, perhaps we should encourage responsiblity
on the part of our subscribers and expect them to watch their mail and use
nomail when they know they will be away.
 
I seem to remember the policy of Yale: delete all bounces, for whatever reason.