** Forged spamming going on

Someone did this to me about six months ago, and yes, there's nothing
you can do to prevent the bounces from coming your way.

I used sendmail 8.9.1's access feature to cause *me* to bounce mail
sent to the forged from address with code:

     550 No such user; forged header address used by spammers

It didn't help me in the AOL case; they don't appear to be watching
for double-bounces. It did help with recipients who tried to reply to
the forged from address.