You might try putting

   Renewal=2005/08/23,Delay(7)  

in the list header, and wait a week - the dropspam subscriber isn't
receiving from the list, so they won't respond to the renewal, and will
be unsubscribed.  This could create confusion and/or annoyance among the
other subscribers, so you'll have to judge that factor against the
irritation of the list owner.  But when you see the unsubscribe report,
you'll have some idea who the problem subscriber was.  And then you put
back your former Renewal selection.

>>> [log in to unmask] 8/23/2005 2:01:28 AM >>>
Perhaps I wasn't clear ... I don't know the recipient!  dropspam.com is
the sender of the message, so I don't even have a clue as to the
recipient or her domain (many hundred subscribers to the list).

The list owner did contact dropspam.com (with threat of legal action)
and dropspam.com opened the list to the subscriber.  So my problem is
resolved for this list and this subscriber, but if dropspam.com becomes
popular, we all could be hit, again and again.  The response gave no
indication they knew their software is broken, but that might be
expected from a front-line tech support.

As for double opt-in, ... my list has most subscribers ADDed by the
list owner.   Should my list owner require double opt-in, the problem
would be tough, but a bit more manageable: LISTSERV's confirmation
request would not get through to the client (I'm not sure where LISTSERV
would send the DROPSPAM.COM "Huh?" message, but maybe LISTSERV site
maintainer 
... with no idea which list or client is involved).  The client would
hear nothing back, and *maybe* would find someone to write to (not
-request, which requires confirmation!).  So client is probably lost to
list, but at least my list owner wouldn't be bugged on every list post!

Thanks again and cheers, wayne