My understanding is if your service provider won't allow a blank subject
line then you can put a period, just one, in the subject line and that
should work when you are trying to unsuscribe or send any message to a
listserv.  Just be sure to omit your signature file from the body of
the message and it *should* work.  John Chadwick, maybe add something
about this to the FAQ the next time you revise it???