Pennyblack comes with automatic bounce detection. Use the following explanation to get bounce detection up and running:
To automatically detect bounces pennyblack uses a patched mailman installation which allows it to pass a email as text and receive a coma separated list of email addresses which have bounced. This is because mailman is published under gpl which only allows direct inclusion if only simple datatypes are exchanged.
Download a copy of mailman 2.x from http://www.list.org/download.html and unpack it into a directory which is on your python path.
Use the mailman_patch included in the gitrepository of pennyblack:
cd Mailman
patch -p1 -i path_to/mailman_patch.patch
Fill in imap credentials in for the sender in the admin and check Get bounce e-mails.