[nznog] Various email issues, including domains without MX records

Hi all I've been paying attention to our mail logs lately and seeing some "interesting" stuff. So I was wondering... Does anyone run a serious (commercial) email operation in New Zealand without having appropriate MX records these days? (i.e. relying on the legacy behaviour of using A records in the absence of MX records.) What about web forms? What about embedded devices? What proportion of valid mail in NZ is sent from an address that doesn't have an MX record? Do you check? What do you do if it's not? If one were to block email from addresses without MX records, how much would break? How many complaints would one get? -Martin -- Martin D Kealey, ihüg engineering