In message <C5EE6366-7EFF-4B7C-BF09-9579C6D24393@xxxxxxxxxxx>, Ted Lemon writes : > On Jul 17, 2014, at 11:26 PM, Mark Andrews <marka@xxxxxxx> wrote: > > There are lots of machines which do not have the SMTP port configured > > yet have A or AAAA records resulting in a implicit MX record and > > week+ long no delivery notifications. > > > > Just about everyone with a outsourced HTTP service needs to be able > > to stop MTAs sending to email to the outsourced service. MUA's > > could also lookup the MX RRset and issue a error without talking > > to the MSA. > > 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? > 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? Is it? You are forcing me to configure a MTA to accept mail for "www.example.com", even if I don't want to, because otherwise I have to trust a hosting service to not run a smtp service on the http server. I'm giving the hosting service stuff I want to be made public. I want to prevent stuff, that should remain private, from being sent to their machine by mistake. > I'm not against this draft moving forward, but I find these use cases > somewhat puzzling. -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: marka@xxxxxxx