Spammers love authentication

I don’t really get this, so I am looking for a little input.

Microsoft is cramming Sender ID down everyone’s throat by making it a requirement for legitimate messages in Hotmail; meanwhile better than 80% of spam already uses some authentication scheme (including, in cases, Sender ID).

Please help me here. What is Microsoft thinking?


J.D. Falk says:

Sender authentication has never been about stopping spam — at least, not by itself. As MAAWG wrote in
a recent white paper ( ), “SPF and Sender ID (as well as DomainKeys, CSV and others) are merely intended to assist the receiver of a message in determining whether or not they can trust a few select (but important) criteria of that message; what the receiving mail system does with that knowledge depends entirely on the policies set by the operator of that system.”