Dave, Steve, John, all: Let me add several thoughts along these lines:
NNTP has since day one had the capability to retrieve headers (HEAD), and later specific headers (XHDR, et al). I tend to think that this isn't enough bang for the buck to completely rearchitect SMTP around such a notion. Early in the discussion, I thought we were talking about the envelope. Validating the envelope seems to me useful, if only because it provides a way to reduce the number of bytes sent, and believe it or not, this is still a problem in certain parts of the developing world, where bandwidth is still expensive. Right now some solve the problem with upstream filtering. That has its own set of problems that are as much political as technical. John mentioned CHUNKING. The reason CHUNKING hasn't taken off is that it was intended to address the idea that it would be possible to run out of resources within DATA, and that this should be signaled. While theoretically possible, I don't know that CHUNKING would have made any difference to either end from this perspective. I don't think it will do much in the context of spam either, since it requires a certain level of cooperation on the part of the client to CHUNK a header. Not that one couldn't encourage it, but is it worth it? Eliot On 10/29/09 10:57 PM, Dave CROCKER wrote: > > Steve Atkins wrote: > >> It would be very, very nice to have an ESMTP extension that >> allowed sending just the headers of an email, waiting for a >> 2xx or 5xx response, then sending the body. And that's the >> general solution to this sort of problem, though a little broader >> in scope than is really appropriate for the DKIM forum alone. >> > Seems like the SMTP Clients with mail that would get dropped after the header > would not be inclined to implement the option. > > But perhaps it would still have uptake, presuming bad authors are different > from > bad transmitters... > > d/ > _______________________________________________ NOTE WELL: This list operates according to http://mipassoc.org/dkim/ietf-list-rules.html
