I was assuming a single list.  Personally I don't see a good reason for
splitting the HTML mail messages away from the non-HTML mail ones.  You
can certainly do what Pete suggests but I wish you luck in making people
adhere to the topics setting :)

IMHO the best solution is to wait for 1.8d and code "Language= NoHTML" in
your header, which will strip the HTML attachments.  I assume the whole
point here is to simply keep HTML mail messages out of your regular
archives (which is, again IMHO, counterproductive since your archives
will not be comprehensive).

Nathan