Sending an email that creates a new issue does not 
work if
the author is unknown:

----  traceback of failure  ----
Traceback (most recent call last):
  File 
"/usr/lib/python2.1/site-packages/roundup/mailgw.py", 
line 141,
in handle_Message
    return self.handle_message(message)
  File 
"/usr/lib/python2.1/site-packages/roundup/mailgw.py", 
line 561,
in handle_message
    content=content, files=files, inreplyto=inreplyto)
  File 
"/usr/lib/python2.1/site-packages/roundup/roundupdb.py", 
line
185, in create
    newid = Class.create(self, **propvalues)
  File 
"/usr/lib/python2.1/site-packages/roundup/roundupdb.py", 
line 94,
in create
    nodeid = hyperdb.Class.create(self, **propvalues)
  File 
"/usr/lib/python2.1/site-packages/roundup/hyperdb.py", 
line 163,
in create
    raise IndexError, '%s has no node 
%s'%(link_class, value)
IndexError: user has no node 2

The line numbers are slightly off due to my patches. 
If you
think they are relevant than let me know and I will 
try again
without them.

Anyway, the database contains only the admin user at 
this time,
and the message sent to roundup should add 
patrick.ohly@pallas.com
as new user, but somehow doesn't:

From:   Patrick Ohly <Patrick.Ohly@pallas.com>
To:     tool-issues <tool-issues@pallas.com>
Subject: [issue] Test of tool-issues
Date:   14 Dec 2001 18:35:15 +0100

tool-issues@pallas.com is the ISSUE_TRACKER_EMAIL.
If the user is added manually the same email creates
the issue just fine.