What am I doing wrong here?

[Skip Montanaro]

Appended to this message is a simple script that uses the
mailbox.PortableUnixMailbox class and email.message_from_file function to
(attempt to) extract a message from a Unix mbox file.  Unfortunately, it
doesn't seem to work correctly.  This code is more-or-less lifted from what
spambayes.mboxutils.getmbox() does.  Any clues about what I'm doing wrong?

Thanks,

Skip