mailbox.py (from the CVS tree) doesn't work with qmail Maildirs:
Filenames are completed when the directories are scanned, and
the directory name is prepended again in the next() method.

Another suggestion: Change the print statement in the _test()
driver to show two more date characters (probably the length
has increased due to the recent Y2K hype ;). Now it shows the
complete date, including the seconds -- at least for me. (I've
also made the sender field left justified, in case it is ever
shorter than the field width).