Creating Sender ID Records As some MTAs start to implement Sender ID checks, domains need to publish these records in order to prevent mails being needlessly rejected.

What is Sender ID?

Microsoft's Caller ID and the SPF standard were combined into a new system called Sender ID in 2004. Sender ID and SPF both depend on checking DNS records published by the sending domain. Whilst Sender ID checking requires adherence to Microsoft licensing there is no license implication in publishing Sender ID DNS records. Several large systems such as Hotmail, MSN and AOL have announced that they will be introducing Sender ID checks. It is therefore sensible for domain owners to publish the records required as soon as possible.

Important Information

At the time of writing, Sender ID is not an internet standard and is not guaranteed to become one. This document is intended to help domain administrators continue to send mail to domains which implement Sender ID checking. Sender ID records may change format as the standard evolves and there is no guarantee of backwards compatibility.

How Can Sender ID Records Be Constructed?

The format of Sender ID records is not difficult, but the records are likely to change as the system evolves. The following sites create records and are likely to be kept up to date.

http://www.anti-spamtools.org/SenderIDEmailPolicyTool/Default.aspx

http://www.spf.pobox.com/wizard.html

Resources

For further information on Sender ID try the following sites:

http://www.microsoft.com/senderid

http://www.openspf.org/