Microsoft Junk Mail Reporting Program - Who Uses This

Anyone else sign up for this?

Did microsoft require your host email them and say "[you] have exclusive sending rights for this IP"?

Here is the part of the email from microsoft:

xx, unfortunately, we have not received an e-mail confirmation from
your ISP, [host], for your IP
x.x.x.x. Please ask them to re-send the e-mail confirmation to [email] with the [id] subject. Please also
ask them to include you on the "To" or "Cc" field in case that we fail
to receive their e-mail confirmation.

Is this a requirement for everybody?

I signed up for AOL's junk reporting program a few months ago and I didn't have to bother anybody about it.

If I recall correctly, all AOL cared about was whether or not my reverse DNS was set properly.