Has anyone else run into concern about keeping list archives
essentially forever?  We would like to have an automatic pruning
facility for list archives, under the control of the list owner.
The primary justification for such a facility is not to save disk
space, but rather that archived email may be subject to subpeona
in lawsuits and other types of legally required disclosure.  Even
if there's nothing embarassing in the archives, the effort to
search the archives of lots of lists could be significant.  So
the list owner should be able to easily specify how long archives
are to be retained.  Some nice things to be able to specify would
be what to do with the old archives (e.g., email to list owner)
and also maybe a warning in advance that archives are going to be
deleted.