One tool that might be useful is the VM MAILER's capacity to forward
mail meant for one user to another.  In the case where a real user gets
a new userid to replace an old one, the user could ask techstaff to put
such a forwarding request in MAILER MTPLATE.  Of course, if you have a
lot of users who want this, MAILER MTPLATE gets very full.  (For how
long?  Give a user a month to get his id's straightened out?)  And,
alas, this doesn't help sites not running the Crosswell MAILER.  (I do
not know if the UCLA MAILER has this capacity.)
 
Someone (Harry?) referred to id's being re-issued.  I know some sites
or nodes assign id's which reflect course enrollment.  We don't take
that approach; for general users, the id is a set of three initials
and the last four digits of student id number (social security number,
usually).  While we haven't run any large analysis of this, we
don't expect problems with two students "expecting" the same id.
 
Lastly, a related problem:  what about users whose passwords may have
lapsed?  Many VM sites (and perhaps other sites, too) lock an account
if a password remains unchanged for N days.  It used to be in VM that
this would cause mail to be rejected; that may still be the case at
many sites.  If I get rejected mail from a site, do I know if a user
is gone or merely temporarily off the system?
 
Nick