I have exactly the same problem. I think the
perpretrators harvest e-mail addresses from these
microsoft newsgroups. Reason I think so is that I have
two e-mail addresses. Only one kept receiving these bogus
messages (at the rate of 25 or so per day). I then used
my other address when I posted in a newsgroup here, and
suddenly this mailbox started getting same bogus mesages,
and at about the same rate.