SPF vs. Sender-ID

• Sender-ID (RFC-4406) is Microsoft’s abomination of SPF

• RFC-2822 layer, or, Header Layer protocol

• Validates a header sender address (purported responsible address (RFC-4407))

• Thank god we talked them out of using XML in DNS...

• But now they use SPF record syntax... confusing!

• Sender-ID spec. directly violates the SPF spec.

• Microsoft refuses to fix it (go figure)