Hi folks. The site's been subject to a couple of thousand signups a day for the past month and a bit, and it's done odd stuff to the registration email sender. I think it might be getting trapped as spam because it's flagging up as lots of traffic to spammy email addresses or something.
Anyway if you have been waiting for weeks to get on the site, I'm very sorry about that, and I hope it doesn't tarnish the rest of your experience.
As for the massive influx of bot accounts, we're either very popular or very unpopular, it's hard to say...