Very nice! On an unrelated administrative note (with apologies for the thread hijack), I think LBO-talk's Mailman should throw away any "Received" headers it gets... perhaps all headers other than the ones it wants to keep. On a philosophical level this is a peeve I have had about Mailman for a long time, since I think that Mailman should not behave like an MTA when it is not one. Ignoring philosophical issues, as a practical matter, such headers contains information that is better withheld.
--ravi