according to a support response to an associate's inquiry:
A spammer initiated a huge attack on the cluster of mail servers that hosts at least one of your domains' mail. We've blocked the spammer and are clearing out the tens of thousands of messages left by the attack. It's made mail slow on this group of machines, and has exacerbated the high load due to MyDoom, the latest Windows virus. All mail will be delivered, just slowly. We're working to ensure that a similar attack won't slow mail down so badly in the future.
live and learn right? That's the nice thing about DH, they usually fix things properly as opposed to the band aid method. No consolation as you wait for your 40 mails but there you go