David MacQuigg wrote:
At 03:33 PM 3/3/2005 -0600, you wrote:
Kevin Murphy of ComputerWire pointed me to the following press
release from MS about SenderID:
If SenderID becomes the most widely-deployed IP-authentication method,
what are the implications for SPF?
I don't see this happening. Just Microsoft saying "SIDF adoption momentum
is quickly growing" doesn't make it so.
| As a result of the growing adoption of SIDF worldwide, Microsoft has
| found notable improvements in the accuracy of its SmartScreen(TM)
| filtering process.
Yeah, right. Hell, why doesn't Yahoo do the same? They could show off
750,000 DomainKeys-equipped domains in a second -- all they have to do is
define SPF to be a part of DomainKeys. ;-)
Can a typical mail transfer, with authentication at each forwarder and
receiver, work correctly when some MTAs used SenderID, and others use
SPF? Or will all stations have to provide both?
That depends on what you mean by "use Sender-ID" and "use SPF".
If you mean that some MTAs use "v=spf1" and "v=spf2/mfrom" records for
authentication of the MAIL FROM and some MTAs use "v=spf2/pra" records for
authentication of the PRA (effectively the headers), then it will work in
a technical sense (i.e. at least it will not break), and it will be all
the more effective the more both sets of MTAs overlap.
If you mean that some MTAs use "v=spf1" records for authentication of the
MAIL FROM and some MTAs use (the same) "v=spf1" records for authentication
of the PRA, then as far as I can see it will not work properly. But,
strictly viewed, we lack substantial amounts of empirical data to
conclusively answer the question.