I don't understand why MH feels it has to do that. There are two options,
from MH's perspective (forgetting LISTSERV for a moment). Either whatever
processes the mail message ignores the "Sender:" field, and MH wasted its
time supplying it, or the "Sender:" field  is not ignored and we now have
a situation where users are tied  to the workstation they actually logged
in  from, which  is exactly  what  a campus  mail server  is supposed  to
eliminate.  I  just  don't  see   the  advantage  of  having  a  unified,
host-independent  campus   address  if   you  then  inject   the  actual,
host-dependent  address in  a field  that  will be  used by  a number  of
automated mail responders.
 
  Eric