>In fact there's even a suggested protocol for it. I don't recall the draft >name, but it works by putting the address list in the DNS. You then use zone >transfer to move the data around and keep it up to date.
Remember the reference? I was thinking of something like that, but if it's already done, all the better. >There are also at least two, and probably more, "lookahead" milters that use >part of an SMTP transaction to perform early address validation. (I use one of >these myself as part of providing backup MX service for a couple of people.) I understand about callforwards, but it seems to me that the backup MX is mostly going to get mail when the main MX isn't available, so I don't see how this would work very well in practice. R's, John
