John,
Just to add to Doug's set of very helpful responses:
* HELO is currently pretty useless because it is not checked, but
encouraging server admins to use the right name can have long-term
benefits.
JGM> Unless you state what these benefits will be, their value cannot be
JGM> determined.
They've been stated. For example:
If the client of an exchange can be authenticated, then
it is possible to develop an accountability mechanism
for it.
...
What is missing is a useful means of authenticating MTA-
MTA exchanges over the open Internet. Prior
arrangement between such a pair of MTAs is antithetical
to the history and operation of Internet mail.
Spontaneous communications are at the core of Internet
design and operation, as well as at the core of many
human interactions. So the challenge is to develop an
authentication mechanism that permits the necessary
amount of accountability, without imposing undue
overhead or restrictions.
JGM> In the Apr 5 conference, the benefit listed was the ability to use a
JGM> domain instead of an IP address as an index into some yet to be
JGM> developed accreditation/reputation service. There are, however,
JGM> numerous RBL services which demonstrate that IP-indexed reputation
JGM> services do work.
What is really ironic about this is that the IP community is working
very hard to move toward host references with identifiers rather than
addresses, and you appear to be arguing for moving in the opposite
direction.
IP Addresses specify a network interface and they are transient. The
real requirement that we are working on, here, is for stable host
references (if the focus is on the transfer channel, rather than the
message object.) Those are different.
d/
--
Dave Crocker <mailto:dcrocker(_at_)brandenburg(_dot_)com>
Brandenburg InternetWorking <http://www.brandenburg.com>
Sunnyvale, CA USA <tel:+1.408.246.8253>, <fax:+1.866.358.5301>