Vista - Windows Mail, et al

Could someone please identify the Microsoft offical newsgroups for the
following programs:

1. Windows Mail (it's something like xxx.xxx.xxx.vista.mail)
2. Microsoft Office Word 2007
3. Microsoft Office Excel 2007
4. Microsoft Office PowerPoint 2007

Also, why do Windows Mail users have to sign into Microsoft Communites in
order to use Microsoft newsgroups? When I had XP and Outlook, you didn't
have to do that.

John