I've had multiple people complain that they haven't received an email when registering a new account. I have no idea what's causing it; the only thing I can think of is that gmail and hotmail are blacklisting the omnitopia email domain for some reason because the emails are in fact being sent out by the server.
To alleviate this for the time being, I've disabled requiring email verification to create an account. If this causes us to be overwhelmed by spambots I'll come up with something else.
I'm planning on switching themes (this one isn't supported anymore) and hopefully I'll be able to implement a better registration system when I get around to doing that.