Been having trouble for a couple of weeks with random outages. After some more investigation, I think we've tracked it down to a handful of rogue servers at two ISPs that appear to be generating massive spam attacks. They have been blocked and we will see how it goes.

Hopefully no legitimate users were blocked. If you are a legitimate user and were blocked, let me know. Oh, wait. If you're blocked, I guess you can't read this.

UPDATE: Well, I guess that wasn't it, or at least not all of it.