UPDATE:
Since April 2012, it is no longer required nor possible to register for Sender-ID manually.
From now on this will happen automatically as long as you have a valid SPF record.
A tool to validate a domain's SPF record: http://www.kitterman.com/spf/validate.html
The following steps will show you how to locate your domain's SPF record and register it with Microsoft's Sender ID service.
1. Login to your cPanel-account (yourdomain.com/cpanel)
2. Click on "Email Authentication" under section labeled "Mail"
3. Copy the line that begins with "v=spf1"
Example: v=spf1 a mx ip4:50.22.76.216 mx:sonicianhosting.net include:sonicianhosting.net ?all
4. Goto Microsofts Sender ID registration page using the following URL:
https://support.msn.com/default.aspx?productKey=senderid&locale=en-us&st=1&wfxredirect=1
5. Enter/Check the following settings:
Contact email address - Enter a valid contact email. You'll be sent a confirmation message to this email.
- Type the name of the domain you want to register
- Select "Yes" here
If Yes, what is the SPF record associated with domain(s) Please separate each SPF record with a semi-colon. - Paste the SPF record you copied from cPanel
6. Click the button "Continue" and your done!
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