-----Original Message-----
From: owner-spf-discuss(_at_)v2(_dot_)listbox(_dot_)com
[mailto:owner-spf-discuss(_at_)v2(_dot_)listbox(_dot_)com] On Behalf Of Chris
Drake
Sent: dinsdag 9 november 2004 10:46
To: spf-discuss(_at_)v2(_dot_)listbox(_dot_)com
Subject: [spf-discuss] OT: Encrypting Proxy question: What
"MAIL FROM:" address is safe to use?
Hi All,
Is there any such thing as a universally accepted "MAIL FROM:"
envelope sender address, from the point of view of ISP MTA's
accepting emails from customers, and where the "RCPT TO:"
addressee is myself (my own MTA on which I can enforce my
own rules) ?
MAIL FROM: <> *must* be universally accepted. There are quite a
few RFC-ignorant mailers out there, though; so caveat deliverer.
I've written a proxy to encrypt emails between client and my server -
it removes then replaces the envelope recipients with the address of
my decrypting server, encrypts the DATA (after inserting my
RSA-encrypted session key and the list of original envelope
recipients), however, I'm not sure how I should handle the senders
email address (MAIL FROM:)
Are you sure this is the right approach? A "smart" host seems more
appropriate for your purposes.
You can forget about "list of original envelope recipients" in case of
MAIL FROM: <>, btw, as a DSN can have only one RCPT TO: recipient.
Also, those who use signed envelope schemes, such as SRS/SES, may not
accept unsigned MAIL FROM: addresses in a DSN.
MAIL FROM: postmaster(_at_)real-senders-hostname maybe?
But then bounces go to that postmaster. He may not appreciate that. :)
Best to look for a different way to do this, methinks.
- Mark
System Administrator Asarian-host.org
---
"If you were supposed to understand it,
we wouldn't call it code." - FedEx