g1smd - 12:21 pm on Jun 23, 2012 (gmt 0)
If you type in an address with 'www' or click on a link containing this you get redirected through to the 'not found' response as set up by your ISP.
Is this "DNS Error" or "Request Timeout"?
Either way you're losing traffic.
Returning 404 is easy. Point the DNS to some place on your server where there are no files. Requests for stuff that is 'not found' will return 404 status and the 'not found' error message.