Mail.app and changing the "dead address" in the Bounce command

[Aaron Dickey]

All--

Ever since Yahoo Mail cheapened up and forcing you to spend $20+/yr for 
the "privilege" of POP forwarding, I've been using YoSucker to grab the 
mail and forward it to another account. That works fine. The only 
problem is, Yahoo Mail being the piece of crap that it is, well over 
50% of the mail I'm currently getting is spam. Mail.app does a ~90% 
accurate job of noting them as junk, but I want to be able to use the 
Bounce command to send back all the spam. And, of course, if I try 
that, Mail.app bounces them saying the address I _forward to_ is 
nonexistent, not the original Yahoo Mail address.

Does anyone know if there's any way to adjust a setting or pref file 
somewhere to force the program to bounce the emails from their original 
address?

Thanks,
--Aaron