have you tried multiple email accounts from different providers, like trying one from gmail perhaps?
have you made sure to see if it is getting kicked to the spam folder?
have you tried to have it resend you the activation code?
if all else fails, you can poke acraig or talad with the mail address you're trying to register with and they'll see if they can do it manually, or see if they can poke the authentication server back to doing it's job.