You may want to check the page that is sending the email... double click the Universal Email server behavior and then check to see if the data binndings "stuck" when you added the behavior. I had an issue once where the bindings didn't stick when I thought I had added them, so I had to go back in and re-add the data bindings. The other thing to check is that you uploaded all of the UE helper files, too.
Cheers,
Brian