First off, my apologies for the server troubles this week - earlier I thought it was that we underestimated the amount of traffic we'd get after Katsu. Now, it's looking more like someone may have hijacked our mail system.
I've turned off notifications again, and we're still looking into the issue, but as of 11:15 am EST it seems to be running ok. We're still working on it!
(Oh, and a double apology to those new members who joined right after Katsu - we're not normally like this...)