Well, Chain Reaction is certainly the admin of nraas.net, so at least that part of the message looks totally legit. I know that the site has a few automatic checks against certain nuisances, like spammers or ddos attacks. Personally, I know not to click several links too quickly.
Can you post in the Chatterbox?
Other than that, the message you showed us tells you how to get access to the site again. If in doubt, carefully check the link (not what is written but what shows when your mouse hovers over it).
Edit: There's also the contact form directly on the site, which is always a safe way to do things:
https://www.nraas.net/community/contactadmin/