Keith Moore wrote:
providing this kind of information is as beneficial to the sender
as it is to the recipient.
right, but it only works for senders who always use the same relays.
I tried to account for that with the domain flag. An organization can
reference any number of individual hosts, or it can reference an entire
domain of hosts as valid senders if it so chooses:
you're missing the point. I might send mail from *anywhere*, from
any host or ISP I happen to be using at the moment. the cs.utk.edu
domain alone represents such a diverse and well-travelled set of people
that it would not be feasible to list the hosts (all over the world)
which might accept their mail submissions and relay them.
also for spam filtering/prevention/remediation it's not terribly useful
to authenticate the sender's email address. what you really want is to
Keith