Referring to:
http://spf.pobox.com/spf-draft-200406.txt
Section 4.3 (in part)
"Usually, the <sending-host> is the IP address of an SMTP client. The
SMTP receiver
is the SPF client. The SPF lookup may also operate after the SMTP
transaction has
terminated. In these cases the <sending-host> may have to be extracted
from the
Received header or some other meta-data about the message. Received
headers can be
forged. Still, accurate analysis is possible if care is taken."
The first two sentences refer to the situation I suspect is not
addressed in the MS patent application. The rest may be in the application,
especially if "a plurality" of headers are examined.
Personally, I doubt the practical truth of the last sentence.
The practicality (though perhaps not patentability) of the MS claims also
appear to hinge on the truth of the last sentence above. The claims
essentially assume the same thing, though I did not see a claim describing an
algorithm for performing the accurate analysis.
Now, way too many people have been shooting their mouths off about what this
patent application contains and doesn't contain. I am not trying to do that.
I am trying to encourage a rational, detailed look at the thing.
I am also not claiming that my interpretation is accurate or in any way
authoritative. I am claiming that the evidence, from this mailing list, the
mailing list of the late lamented MARID, the statements from well placed
Microsoft employees and from at least one Microsoft PR guy, indicate that true
understanding of the contents of this patent application is a rare, perhaps
nonexistant, commodity.
This thing matters! Whether we like it or not, it affects the future of domain
authentication. Even if the whole thing were eventually denied by the USPTO
and any other patent offices it has been submitted to, it will still create FUD
during the several years that would take to happen. We need to know what it
really says. It is bad enough to have a threat hanging over the field. It is
even worse to have a poorly understood, much subject to rumor, threat hanging
over the field.
Mark Holm