From: scott@budomail.com

We are having problem with spam getting sent to our
roundup email account. We are using spam filtering
which is pretty good, but occasionally some spam gets
through and it breaks the roundup system.

Roundup is failing to retrieve email because it fails
to deal with a 550 unknown account error that is
generated when it tries to send a bounce message saying
that anonymous user postings are not accepted.

Clearly, this is very common because it is rare for
spam to have a valid return address.

Traceback (most recent call last):
  File "/usr/bin/roundup-mailgw", line 3, in ?
    run()
  File
"/usr/lib/python2.3/site-packages/roundup/scripts/roundup_mailgw.py",
line 189, in run
    sys.exit(main(sys.argv))
  File
"/usr/lib/python2.3/site-packages/roundup/scripts/roundup_mailgw.py",
line 163, in main
    m.group('pass'))
  File
"/usr/lib/python2.3/site-packages/roundup/mailgw.py",
line 445, in do_apop
    self.do_pop(server, user, password, apop=1)
  File
"/usr/lib/python2.3/site-packages/roundup/mailgw.py",
line 481, in do_pop
    self.handle_Message(Message(s))
  File
"/usr/lib/python2.3/site-packages/roundup/mailgw.py",
line 549, in handle_Message
    self.mailer.bounce_message(message, [sendto[0][1]], m)
  File
"/usr/lib/python2.3/site-packages/roundup/mailer.py",
line 139, in bounce_message
    self.smtp_send(to, message)
  File
"/usr/lib/python2.3/site-packages/roundup/mailer.py",
line 166, in smtp_send
    raise MessageSendError("Error: couldn't send email:
%s"%msg)
roundup.mailer.MessageSendError: Error: couldn't send
email: {'Susana': (550, 'Susana unknown user account')}

Logged In: YES 
user_id=6405

The mailgw is now handling this error when it bounces invalid 
mail. The bounce message is discarded if the only error is that 
the address is invalid.