While this preventive  maintenance is a good idea for  sites which have a
lot of lists,  I am afraid that, generally speaking,  netwide signoff and
the like do not have much of  a future. This mechanism was implemented as
a  short  term  solution  to  a problem  for  which,  unfortunately,  the
"network" did not provide any  long term solution. Picture the situation.
You are the manager of a real  estate company who owns a number of villas
and rents  them to people. Joe  just left the "Blue  Nightingale" and you
are going  to rent  it to  someone else. Unfortunately  it seems  Joe was
subscribed to  a number of magazines  that might, er, have  a negative PR
effect on the next prospective customer to visit the house. Do you:
 
1. Pick up the  magazines as they come in and  tell their publishers that
   Joe no longer lives here?
 
2. Tell the post office to block all incoming mail for Joe?
 
3. Look up the names of all the publishers in the country and mail them a
   letter  saying that,  in  case  Joe was  subscribed  to  any of  their
   publications, it would be nice if they could stop sending them to this
   address?
 
Let's face it, what we are doing makes no sense at all. The reason we had
to do that  is that choice 1  was not practical, just like  in real life,
while  choice 2  didn't work,  because the  post offices  in the  various
villages couldn't  agree on the  language in  which to notify  the sender
that Joe  no longer lives at  the "Blue Nightingale". 3  was an emergency
solution,  and we  had hoped  that the  post office  would get  their act
together.  Unfortunately they  haven't,  but as  the  network grows,  the
number of lists  grows, the number of subscribers grows  and the machines
don't grow because  they run politically incorrect  operating systems, we
will have to stop doing that some  day, meaning we will be back to choice
1.
 
Regarding deleted nodes, however, the problem  will be solved in the next
version of LISTSERV (or with  development fix 17E-002D) for servers whose
local  mailer  is LMail.  LISTSERV  can  understand the  delivery  errors
generated by  LMail and will delete  the old addresses the  first time it
attempts to post  to them. This does  not of course solve  the problem of
deleted accounts,  as the target  mailer is  then the one  generating the
error, but at least one of the problems is solved.
 
  Eric