That's odd, I would have thought that '404 Not Found' would be the wrong response to send, although you could argue either way. I used to develop a web server

That's odd, I would have thought that '404 Not Found' would be the wrong response to send, although you could argue either way. I used to develop a web server ages ago (Zeus Web Server), it would try and match the Host: header against all the sites it was configured to server, and if none matched, it would send a 400 error back. (Incidentally, it would happily strip off the trailing dot from the hostname)