John: Yes.
 
(I thought I would answer positively :)
 
No, in reality, there is no such feature as autodelete, as far as I can
think on a Monday morning. There are just so many different replies
from mailers that it would be almost impossible to write something
that would catch all cases, and not to have to update the code
every few months. The danger of removing someone "innocent" in the process
is real, and that would be my worry about a such autodelete.
 
Btw, thanks to Eric for letting me blabber on this list too.
Regards, -turgut