Detecting bounces

Hi,
        How can I detect bounce messages from all kinds of MTA's?  I know how
to detect bounces from sendmail and qmail, but all the systems I've encountered
seem to do it somewhat differently.

Thanks for any information.

-- 
  Matthew Harrell                          Programmer - a red-eyed mumbling
  Simulation Technology Division, SAIC      mammal capable of conversing with
  mharrell(_at_)std(_dot_)saic(_dot_)com                     inanimate objects.