Where are you seeing this error?

I just tested Elinkworld.com

Thanks for following up with me on this. I believe this is likely nothing to worry about, as the scan is only detecting the IP address of the domain itself, and is expecting a postmaster address associated with it. Do you have this IP set up as a hostname on IIS or within SmarterMail anywhere?

I have smartermail on it's own IP.  I do have iis running the web interface on a different IP and my main website is on a different ip.. 

I was thinking how I enter 2 mx records for this too as the email is on one IP and one mx record points to that but if I use the 2nd record as the domain it's pointing to the wrong IP and errors out as a bad record haha :)