Al, there's one thing I can suggest that you try on your own:

With Enourage not running, click on it to open and IMMEDIATELY press the Option key and keep it pressed. In the Database Utility window that you'll see next, pick the Rebuild Database option. The rebuilding will take a while, so don't do this at a time when you can't wait to do email.

When that's finished, either your problem will be fixed or I need to make a house call.