Logged In: YES 
user_id=12800

It doesn't look like anybody has the motivation to fix
mailbox.py so I will (finally!) add this note to
libmailbox.tex (for both Python 2.3 and 2.4):

\note{For reasons of this module's internal implementation,
you will probably
want to open the \var{fp} object in binary mode.  This is
especially important
on Windows.}