It is fairly easy to mess up signature dependencies of required modules if there's no clear indication what version of Python is exactly required.
Everybody seems to invent his own templating tricks when using Python.
ezmlm might be powerfull and trouble-free stuff, but it is really hard to find a decent web mail archiver which runs directly on the Maildir archives. Too hard.
I'm normally not used to work with open source code with no community around it. It is scary to work with code coming out of some obscure SF CVS module, with a mailing list archive of only 15 messages over 1.5 years. Commit messages, that is: I found no trace of real, human communication. :-)