Microsoft is joining more than 36 companies in participating in the second annual Email Authentication Summit in Chicago. Microsoft announced "strong momentum" in its work with other technology industry leaders to help promote email safety. Included in this strong momentum is the heightened use of the Sender ID framework for e-mail authentication, as well as the launch of an enhanced MSN Postmaster Services program. The program is designed to assist email senders and ISPs to manage their outbound email infrastructures better.
http://www.securitypronews.com/news/securitynews/spn-45-20060419MicrosoftShowsStrongMomentuminEmailProtection.html

Microsoft/SenderID:
http://www.microsoft.com/mscorp/safety/technologies/senderid/default.mspx

Urs