[afnog] AOL rejecting hosts with no rDNS?

[Brian Candler]

On Mon, Jun 28, 2004 at 09:59:15AM +0200, Phil Regnauld wrote:
> > Quite. In any case, the fundamental point seems to have been missed: people
> > seem to believe that fixing forged envelope senders will prevent spam.
> > That's just a total non-sequitur.
> > 
> > Do they *really* think that spammers cannot make their mails SPF-compliant?
> 
> 	No, SPF is here to protect brand names, as Paul Vixie put it.
> 	It will "garantee" that no one can spam in Yahoo's name, or Hotmail's.
> 	This opens a perverse loophole...

So, we have problem X with Internet mail, and since we can't agree on a good
solution for problem X, we try to fix problem Y instead?

In any case, SPF (at least in the form it was 2 months ago) does not protect
brand names at all. It tries to prevent someone using your domain name as an
envelope sender (MAIL FROM). That is all.

Envelope senders are never used except when handling undeliverable mail;
upon successful delivery, the only thing which happens is it may be recorded
in a Return-Path: header, which is normally hidden from the end-user.

It doesn't affect what goes in the From: header at all, which is what the
end-user actually sees.

Worse, SPF breaks common and legitimate uses of E-mail, like forwarding.

So in summary: it's a bad solution to a non-problem.

Brian.