smtplib

[{USER_FIRSTNAME} {USER_LASTNAME}]

I am trying to write a simple smtp mail form for a website.  It seems that
the code that i wrote is working fine but I keep getting the following error
from the Python Shell:

SMTPRecipientsRefused: {'dbenson at nothingspecific.com': (550, '5.1.1
<dbenson at nothingspecific.com>... User unknown')}

When I try and use the same code as an external object in Zope, I get a
"host not found" error.

Any suggestions??