My email is rawr [at] rawr.mp and when I tried to enter it correctly it said 'Please enter a valid email address.'

I changed my email to a gmail.com one and it worked fine. So is .mp not being accepted by the system yet?

.mp isn't a valid one I've heard of before. Where abouts is it from?

IT's a new site/domain that's available.

http://chi.mp is the area that it's mainly from. It's where people can own their own personal 'profile'... And also you can purchase your own domains. When you create your area, you can have an email redirect to another email... hence the email addresses.