Thank you all for responding. I have taken senor_jt's suggestions and just moved my email to Google Apps. It's free, and I had my emails setup in less than 10 minutes. Still no word from DreamHost support other than the email below:
I'm terribly sorry about the problems you experienced with your mail.We had a bit of an issue last night that caused some of the password file on your mail cluster to become corrupted. We had to regenerate those, one
at a time, to restore service. This task takes an hour or two, however, should be completely fixed now!
Again, I'm terribly sorry about the problems this caused. If you need anything else, please let us know.
Still no response to my question, and the "had a bit of an issue" seems reminiscent of their "funny" billing issue at the beginning of the year. I am trying to run a business and cannot have providers with "a bit of an issue".
Thanks again for your responses.