If you're trying to filter the messages, try to filter on the X-ML-Name 
header. If you're trying to reference the message number, look at the 
X-Mail-Count header. Of course, it would have been nice to have a wee bit 
of warning and maybe a transition period so we could update our filters... 
;)

--On Monday, January 07, 2002 16.09 +0900 Jack Dempsey 
<dabigdemp / hotmail.com> timelessly enscribed:

} Why is it gone? kinda hard to organize the e-mails now...