wayne,
One attempts to certify a relationship between an MTA and a message
author.
w> I'm not sure what you mean by "author", but I'm guessing you are
w> talking about the From: and/or Sender:
I mean From.
Sender is the agent that posts it, not necessarily the agent that wrote
the content.
w> When
w> you get to the point of identifying a particular author, I'm not sure
w> that it is so important to worry about the MTA that the email was sent
w> from.
My reading of the majority of the MTA Authentication schemes is that
they purport to validate authorship (and, therefore, really are making
statements about the From field) based on having the message transit
authorized MTAs.
The other attempts to certify a relationship between an MTA and the
network that that MTA operates in.
w> You left out the relationship between the sending MTA and the domain
w> used in the HELO and/or MAIL FROM commands.
What relationship do folks think this is (or should be) between the EHLO
domain name and the network the MTA operates in?
As for Mail From, that is a bounces address, and is not required to have
anything at all to do with authorship. There are entirely legitimate
uses that set the Mail From to an address that is entirely different
from the From field.
d/
--
Dave Crocker <dcrocker-at-brandenburg-dot-com>
Brandenburg InternetWorking <www.brandenburg.com>
Sunnyvale, CA USA <tel:+1.408.246.8253>