Let me start by saying that, like most people here my email is rather screwed up. The wrong addresses now “own” the wrong mailbox. These are all personal addresses so I can work around this but others may not be able to.
However I can see why this change was needed.
The real problem here is the process of change control. Dreamhost is no longer a small company with one server and a bunch of friends running it. It’s a business. Thousands of customers rely on it. On the one hand Dreamhost is a great company. They support new ideas and technology (Jabber, WebDav) and with the new voting system they are responding to their customers desires.
The one major problem is change control. Testing may or may not be done, but in this case the customers were not told what was going to happen.
Regardless of how well the “old” email setup worked, it was the system everyone was used to. Email is a critical part of a hosting plan/company. To make a MAJOR change like this without giving everyone prior notice is appalling. The customers should have been giving several weeks to assign each address to a mailbox and sort their forwarding out manually. I cannot believe this sort of change was made, and the customers were told as an after-thought.
To Will, Josh et al. You listened to our complaints after the DOS problems. New Routers were deployed and status.dreamhost.com was setup. After this event, please develop sound change control procedures and inform us well before you make major changes. I’m sure whoever deals with the support queues would also agree.