Frank Ellermann <nobody(_at_)xyzzy(_dot_)claranet(_dot_)de> wrote:
"Final delivery" is something different, I'd say "sent" where
you say "delivered".
Which is part of the confusion. The Simple Mail Transport Protocol
transported the message from origin to destination. That's
"delivery", by at least one standard.
When a FedEx guy hands my receptionist a package, he's "delivered"
it, for all intents and purposes. The receptionist may, in turn,
deliver it to me, but that's a different kind of delivery.
Much of the confusion around these discussions has been a result of
the terms being overloaded, and the participants not qualifying the
context in which they use the terms.
There's no problem, the MX can be a gateway to some fascinating
UUCP forwarding, or forward your mail to an MDA, with several
hops, it's all fine and still MAIL FROM you RCPT TO recipient.
Once the MX for your domain gets the message, any final steps to get
it to your physical mailbox is *internal* to your site. It varies
from site to site in a way that SMTP does not.
It is _not_ the historical approach, that's only a legend of
the "bounces-to" camp.
<shrug> For me, it's all "he said, she said".
The MAIL FROM _semantics_ is as it always was since STD 10. And
SPF simply uses it to fix this security loophole in SMTP today,
for those who want it.
And there's the sticking point: "those who want it".
It's about consent. Two adults consenting to do stupid things is
not something anyone can control or prevent. Yet there's been
significant effort in the SMTP community to do just that.
Alan DeKok.