Hurray! I finally forked a github project. Yesterday I ran into the bounce-email gem by Agris Ameriks on Rubyforge. It’s basically a 1:1 port of the PHP Bounce Handler classby Chris Fortune and not very rubyified. Thanks to David Reese, bounce-email is forked on github and I could easily extend it.

I rubyfied the class, did some code cleanup, added (yet a very simple) way to get the original message, and gained some performance by paring message only on demand. A testcase was broken as well the Rakefile, both are fixed. See the update here:
http://github.com/rngtng/bounce-email/tree/master