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> -----Original Message-----
> From: [email protected]
[mailto:[email protected]]
> On Behalf Of SM
> Sent: Thursday, February 26, 2009 10:05 AM
> To: Hector Santos
> Cc: [email protected]
> Subject: Re: Concluding the SPF and Sender ID experiments
> 
> 
> Hi Hector,
> At 05:28 26-02-2009, Hector Santos wrote:
> >I don't see the logic connection.
> 
> The first part of the comment was about the note.  That note mentions
> how the two experiments can affect each other.  It goes on to say
> that the heuristics could be applied incorrectly.
> 
> >A SPF hard fail result is a strong indicator that the DOMAIN wants a
> >rejection - no guessing, no 2nd thoughts.
> 

+1

> There was a comment about phishing and that receivers use the
> pass/fail from SPF1 tests as a strong indicator to assess the
> validity of the message.
> 

No, what I meant (or intended to communicate) is that testing in
conjunction with receivers has shown a very high correlation between
phishing emails and SPF failures where the abused domain has published a
strong SPF record (ending in -all). 

> >For us, the whole point of SPF1 is not to use heuristics at the SMTP
> Level.
> 

No heuristics. If a domain publishes a record using "-all", they are
indicating that mail not originating from the hosts indicated didn't
originate from them. IBM publishes a simple -all for ibm.com. That is a
statement that if you receive connections for mail (Mailfrom) purporting
to be from the domain ibm.com it isn't their mail.

> It is used for heuristics at the 5322 level.
> 
> >But hard fail at SMTP transport level? ---> REJECT!

+1
> >
> >System that ignore the hard fail policy of a domain are just
> >creating problems for domains that desire it by watering down the
effect.
> 

+1

> Do these domains publish v=spf1 and spf2.0 records?

Mine do but the spf2.0 is just to specify mfrom to avoid the use of PRA
against our domains.

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