According to:
http://www.zdnet.com/zdnn/stories/news/0,4586,2315106,00.html
------------------------------------------------------------------------------
AOL can't trademark 'You have mail'
Court says AT&T can use phrases including
'buddy list,' 'IM' and 'You have mail.'
WASHINGTON -- AT&T Corp. said it won
the go-ahead on Friday from a U.S. court to use slogans and
service names popularized by rival Internet services provider
America Online Inc., in the latest setback to AOL's
efforts to fend off competition in its consumer businesses.
[...etc...]
------------------------------------------------------------------------------