[TYPO3] mailformplus and preprocUserFunc or saveUserFunc

[John Nicholas]

I have a mailformplus where the client would like a different user email 
  sent based on one of the drop downs. I've looked closely at the 
preprocUserFunc and saveUserFunc but they don't appear to be able to 
modify anything. I'm guessing they are there just for tying in external 
systems.

What I'd like is to have a field, something like a drop down for 
Products ("widgets","pets","kites"). If a user selects "widgets" they 
get an email that is about that, "pets" they get a different email and 
so on.