You can have automatic expiration (well automatic subscription renewal,
the subscription being cancelled if not explicitly confirmed), but this
is on a list-per-list basis. For example, I could set up LSTSRV-L so that
you all got a warning every 2 months that you are on it and you have to
confirm your subscription. But there is no way for me to tell all the
LISTSERVs that LEPICS userids have to be kicked off all the lists after 2
months, if that is what you were looking for.
Eric