Those pesky s*bscr*b*/uns*bscr*b* messages

[ Let's try this again.  The first message *uns*bscr*b*d* me!?!  When
  reading this message, replace the * in s*bscr*b* with the
  appropriate vowels. ]

I'm getting tired of those pesky s*bscr*b*/uns*bscr*b* message that
certain "other" mailing lists seem to pass through to the list at
large instead of capturing them at the list server, like SmartList
does.

Has anyone come up with a sure-fire method of dropping these extra
messages, without mistakenly dropping a real message?

My first thought would be to filter on

  ^^(un)?s*bscr*b*

but that would drop messages that just happen to start with either
s*bscr*b* or uns*bscr*b*, with no regard to the rest of the message.

Then there is 

  ^^(un)?s*bscr*b*$

but this would miss s*bscr*b* messages like

  uns*bscr*b* foo(_at_)host(_dot_)bar(_dot_)com



If no one has anything, I'll start experimenting.  I've got quite a
few messages to test with.

[ For what it is worth, I think SmartList is a little bit too liberal in
  its interpretation of unsubscribe messages. ]

Rodger Anderson