You need to mail someone at UIUC... but I don't know the procedure as that was lost long ago. However, I will chime in with a reccomendation... the following is always the last item I see on messages I get from the Galileo mailing list- I think it is very helpful and not at all intrusive to include this information with every message. I think it would be great if the list server for Squeak were able to append this to the messages it sends out.
(begin) # # # # #
You are subscribed to the Jet Propulsion Laboratory's galileo listserv. To unsubscribe, e-mail JPLNews@jpl.nasa.gov . Leave the subject field blank, and type unsubscribe galileo in the body of the message.
(/begin)