I have not gotten to see the files describing Eric's LISTSERV yet,
 
One feature I am interested in is whether or not this list server
can be told that if mail is received from a particular origin, it
is to be sent out to everyone EXCEPT NOT to the sender.
 
With such a feature, it should be EASY to chain servers together
without either looping problems (which this LISTSERV may have other
ways of avoiding) or requiring users send mail to a central server.