Dreamhost should stop advertising IMAP email or webmail with their plans, because they have proven over the last 6 weeks that they can't competently provide those services.
Constant downtimes during business hours over the last 6 weeks has given me so many migraines, and the "look how happily stupid we are" support responses are getting REALLY old. That stuff is great normally, but if you have provided barely functional service to your paying customers, you could at least take their frustrations more seriously. You could also update your "status page" with timely and correct (imagine that) information. I can't tell you how many times I've read "everything's peachy now" only to be made a fool a few minutes later.
I've been a customer for 4 years, and I can't wait to say goodbye to this horrible email system. I am flipping the MX switch over the weekend and will be moving everything else off of these servers soon. You guys have obviously out-scaled whatever network setup you have been using. My only regret was that I didn't make this switch after the first week of problems. I erroneously believed that you were serious when you said you would fix the problem.
To anyone considering using Dreamhost for something that requires a reliable email system, keep looking for another host, because these guys can't do it.