spf-discuss
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Re: Why will SPF stop SPAM

2004-08-17 06:27:47
On Tue, Aug 17, 2004 at 09:09:16AM -0400, Holm, Mark wrote:
There is a possible point for SPF developers here.  Perhaps SPF checkers 
should offer the option to kick out a flag or add a special header when they 
see a   +all

Seems like a +all, though formally a legal part of the syntax, is a pretty 
clear indication that something is wrong.  At the very most charitable, it 
should be interpreted as an unknown.

Reminds me of the old hypothetical PDP-11 instruction Mov -(IP) -(IP).  
Formally, a legal part of the (highly orthogonal) instruction set, but 1. Not 
usually implemented and 2. producing a pretty bad (though amusing) result if 
actually executed.

We've been over this a while back. To summarize:

- spf gives the domain owner the option to publish a policy he seems fit
  for that domain, rejecting certain policies reduces this option
- it is easy to come up with records to the same effect that don't have
  +all in there (using include / redirect / ip4)
- those publishing a +all will in a spf-dominant world suffer from 
  forgery, and thus end up on rhsbl's pretty soon

Koen

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