Vista - deleting undeleteable mail

I had one of those undeletables with the "unknown error" message just a few
minutes ago after just installing the Vista upgrade yesterday - saw a comment
on a Judy having a solution - read it and freaked:{
What a lot of work - so this mail was in a folder of mail that I save - made
a new folder for the mail in this folder moved them all to the new folder and
deleted the folder with the bad email in it - I have mine set so the delete
folder empties when I close the program - closed the program - opened it back
up - no more bad mail