On Jan 13, 2008 9:55 PM, Tony Finch <[EMAIL PROTECTED]> wrote: > On Sun, 13 Jan 2008, Suresh Ramasubramanian wrote: > > > > One operationally better way to go seems to be Mark Delany's mx0dot > > proposal, which started out as an internet draft, but seems to have > > lost momentum .. the concept is sound though. > > Exim implements this convention.
Er, the concept is DNS related .. totally MTA independent. Simply declaring that there is no MX record in a way that stops fallback to an A record. Exim would check for such. Other MTAs, even those that dont explicitly check for it, would try to deliver email and fail immediately, creating a 550 / NDN / whatever. Basically - > To indicate that a domain never accepts email, it advertises a solitary MX RR > with a RDATA section consisting of an arbitrary preference number 0, and a > dot terminated null string as the mail exchanger domain, to denote that there > exists no mail exchanger for a domain. > > The dot termination denotes that the null MX domain is considered to be > absolute, and not relative to the origin of the zone, the behavior of dot > termination and the formatting of this record is as described in STD13 > --srs
