I'm now checking it in. I need to write some documentation for it,
but I don't have time right now. Still, I wanted to get this into
2.1a2.
# Overview:
#
# This file implements the minimal SMTP protocol as defined in RFC 821. It
# has a hierarchy of classes which implement the backend functionality for the
# smtpd. A number of classes are provided:
#
# SMTPServer - the base class for the backend. Raises an UnimplementedError
# if you try to use it.
#
# DebuggingServer - simply prints each message it receives on stdout.
#
# PureProxy - Proxies all messages to a real smtpd which does final
# delivery. One known problem with this class is that it doesn't handle
# SMTP errors from the backend server at all. This should be fixed
# (contributions are welcome!).
#
# MailmanProxy - An experimental hack to work with GNU Mailman
# <www.list.org>. Using this server as your real incoming smtpd, your
# mailhost will automatically recognize and accept mail destined to Mailman
# lists when those lists are created. Every message not destined for a list
# gets forwarded to a real backend smtpd, as with PureProxy. Again, errors
# are not handled correctly yet.
Tim Peters