The only clue I have found so far is "sendmail will not expose the MAIL
FROM: sender address by default. So
if you're using sendmail, please add this to /etc/sendmail.cf :
H?l?X-Envelope-From: $f
Does that make any sense?
I've seen that on a SpamAssassin page, and I'm not sure where it came
from. Sendmail inserts the envelope sender into the Return-Path for any
mailer that asks for it (which the local and procmail mailers do by
default). Granted, the actual macro is $g, which could be confusing, but
for all intents and purposes and in most normal configurations, that
ends up being the same as $f (envelope sender).
In fact, the docs for the SA SPF check stuff now say that Return-Path is
checked, IIRC, so they seem to have gotten the memo. :)
It's also worth noting that Stephane's example uses Return-Path, as
well, so you don't even need the H line for that.
--
Mike Markley <mike(_at_)markley(_dot_)org>
"You're out of your mind."
"That's between me and my mind."
- Simon Tam and Jubal Early, Firefly: "Objects in Space"