The Sender ID Framework is an e-mail authentication technology protocol that helps address the problem of spoofing and phishing by verifying the domain name from which e-mail messages are sent. Sender ID validates the origin of e-mail messages by verifying the IP address of the sender against the alleged owner of the sending domain. Now adopted by more than 10 million domains worldwide, Sender ID is providing brand owners, senders, and receiving networks with significant business and technical value.
If you have not already done so, I highly recommend you create an SPF record for your domain as this will make it much more difficult for spammers to forge your domain in order to spam domains in other organizations. Creating your own SPF record is a relatively simple process, Microsoft even provides a web-based GUI wizard that will help you do this
Sender ID Framework SPF Record Wizard
This four-step wizard will guide you through the process of creating a new SPF record for your DNS domain. You should add this DNS record to your domain’s DNS configuration. Note that you may need to manually edit the SPF record created by this wizard if you want to use some of the more advance features of the SPF format. For complete details please refer to the SPF record specification at http://www.microsoft.com/senderid.
How does Sender ID Framework work?
1. Sender sends an e-mail to Receiver.
2. Receiver’s inbound e-mail server receives e-mail and calls its Sender ID Framework.
3. The Sender ID Framework looks up the SPF record of the domain that Sender is using for sending the mail.
4. The receiving Mail Transfer Agent (MTA) determines if the outbound Mail Server IP address matches IP addresses that are authorized to send mail for the user.