[Mailman-Users] Block spam from "-owner"?

[Jon Slater]

I am getting a great deal of spam to almost all of my lists.  Well, not the
lists per se, but to the owner's of the lists.  

 

Like:

members-owner at server.org

volunteers-owner at server.org

board-owner at server.org

 

I'm using SpamAssassin but these are coming in with spam score like "-0.6"

 

Is there some other mechanism for eliminating this spam?

 

Thanks!

 

Jon