Seems to me that getting all of the other-net list mailers to implement
a complete solution would be difficult.
 
Perhaps a satisfactory alternative that is implemented totally within
LISTSERV would be to allow lists to be declared "subserviant" in addition
to peered.  A subserviant list would have a "master" on another
network.  Mail traffic apparently from the master (identified by either
which network it came from, or which user from a list of possibilities,
or...) would be distributed as per normal.  Mail traffic not from the
master (probably meaning from a Bitnet host) would be forwarded to
the master AND NOT DISTRIBUTED.  (I assume we'll catch a copy returned
by the master and distribute that.)
 
 
-JSFisher