----- Original Message -----
From: "Andy Bakun" <spf(_at_)leave-it-to-grace(_dot_)com>
Sent: Monday, December 06, 2004 2:03 AM
Subject: Re: [spf-discuss] Re: RFC 2821 and responsibility for forwarding
On Sun, 2004-12-05 at 15:36, Frank Ellermann wrote:
> I thought this thread was on-topic
It is, and in fact it helped me to find out that Meng's idea
of local white list does not cover all cases where SRS isn't
good enough (or where a forwarder simply hates the SRS idea)
Your "big ISP" example was convincing, they cannot offer a WL
for their customers, because SPF tests based on the RCPT TO
are a technical nightmare (probably impossible).
Heh, success! :)
I vaguely remember someone had generated a matrix of forwarding
solutions so they could be easily compared. Unless I'm mis-remembering,
I can't seem to find this now.
I hate being up this early. New job, too excited, but at least there's
something interesting to read.
The big ISP example is a case where SPF blocking may not work well, but
using SPF as a scoring factor for other systems might. For example, a
SpamAssassin system can easily score failed SPF results as very negative,
allowing the user to overwhelm that score with a large whitelist score. This
works well for people who get certain mailling list mail that don't use more
modern tools such as mailman, which handle the sender information better
than a mere forwarding service.