I guess what is needed is either a way for NETNEWS not to put its address
in  the "Sender:"  when the  list  gated to  is  public (or  maybe use  a
different package for  this gateway function), or some  sort of exclusion
list with addresses that can't be hit  by the spammer. But, of course, if
spammers find out that [log in to unmask] is a "protected" address they
will quickly abuse it...
 
  Eric