I wonder about the command called "authentication =on?"

We have a person using netscape to change his email
addresss and he is using the name of the listserv
owner when he does this to post pretty
vile things.

I heard there was a way to "string match" the
domain after the @ sign in the message ID to
the string after the @ sign in the return email
address. I was told that was placing a
section called "Authentication= on" in the
listserv headers where all the filters and
listserv setups are.

In other words

if message ID says [log in to unmask]
and the emailers name is [log in to unmask]
the "authentication= on" would reject it the
same way filter would and send a message
back to the sender to that effect.

Can anyone tell me about that listserv feature?
Is it possible? I was also told it is a
feature called "verificaton=on" in older
listserv software.


Can anyone give any insights to this?

The site that is allowing this guy to post is
ucsd.com and they do NOT reply to abuse
and postmaster complaints.

Thanks for any leads on this.