[Kevin Peuhkurinen]
To my mind, there are ZERO hinderences to Microsoft
adopting SPF, but there are plenty of hinderences
for most everyone else to adopt the encumbered
Sender-ID.
SPFv1 does not address email header forging at all. So SPFv1 does very
little to prevent forging of the "from" addresses seen by the user in
99% of MUAs. SPFv1 therefore does very little to prevent phishing scams.
This is why Microsoft came up with CallerID for email, and why Meng and
MS decided to merge the best parts of SPF and Caller ID into SenderID
approaches.
So yes, there are very big hinderances to MS and everyone else adopting
SPF classic - it doesn't solve a big part of the email forging problem.
Even "Unified SPF" still defines the PRA algorithm for use in verifying
mail headers, and therefor is also incumbered by the Microsoft IP.
--
Ryan