Can you use the send email tool to test if you can get mail messages delivered from the Control Panel:
CP -> Tools -> Send Mail
Are all files currently running on your site stock/untouched from the install archive (no modifications)? Have you tested with the original email address? Are your UBB.threads email settings correct? Have you checked in any spam folders on the account you're sending from and your account you're supposed to be getting mail at? Does the UBB.threads log indicate the messages are being sent?
