#5.1.0 smtp;550 5.1.0 Authentication required   

I have a single domain that my users can not send to.  This is a Win2003, 
Ex2003 with all patches applied.  The ISP is comcast we are not using a smart 
host.  The domain is baby-nova.de.  The message is "started outbound transfer 
of message" and the NDR is generated.  Any help would be very much 
appreciated.

date: Wed, 19 Dec 2007 07:24:06 -0800   author:   jgreenwell