Here's part I.
Thank you for contacting Sender ID support. We are in the process of providing a more robust support experience for the Sender ID Framework program. You can reach the support and submission form by submitting your request at our website: http://support.msn.com/default.aspx?productKey=senderid&mkt=en-us.
This is now an unmonitored alias - please use the above website to submit your request.
Thank you -
The Sender ID Framework Support Team
I stand by my original assertion that having to register an SenderID/SPF record is stupid.
Most spam filters check the SPF automatically by doing a DNS lookup on receipt of mail, but Microsoft insist that you register your domain with their SenderID program.