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