> Has anyone here successfully implemented a system of list
> expiration/renewal at their site?  I don't mean *subscription*
> renewal.... for example, if a user requests a list on my server, I want
> to be able to track the age of the list and then know after, say, 6
> months, get rid of it.  I find this desirable because professors often
> request lists for their classes, which, of course, usually last only a
> semester.

We implemented a program of our own on top of the Solaris version of LISTSERV.
It looks at the list archives to determine which lists are inactive (or the
date the list header was last modified for lists without archives).  We send
three warning messages to the list owners at intervals of a month before
deleting the lists.  List owners can ask that their list be retained.