>I must be missing something here. You're saying you want me to set up a null MX for all my hosts to >prevent someone else's MTA having undeliverable mail sitting in the queue for a week? Why would I care >about your MTA's queue? Why would this issue even be on my radar? To get a definitive answer, you'd have to ask some of the many people who already implement null MX. In my case, it's partly because my own users mistype names and the typos happen to be names that resolve in my DNS, and partly because people write and say "sorry, I wrote to ask where to send your $50,000 check and I just saw that I mistyped your address a week ago." >The second example you give, stopping mail being delivered to the web server, is actually served better >by setting up a proper MX that directs the mail to the right server. Does an HTTP server really care >about the occasional SYN to port 25? Well, OK. What would be the proper MX for mail sent to ted@xxxxxxxxxxxx ? R's, John