Actually, I just checked. Right now, none of them seem to publish SPF RRtype
records.
Yahoo doesn't even publish a TXT record containing SPF information. An
argument could
be made that if we really wanted to push the adoption of SPF RRtypes, getting
Google,
Yahoo and Hotmail to publish SPF RRtype records would actually make it
worthwhile to
query SPF first, because most queries probably go to those domains.
This would require some reason why it is worth them spending time and
money to do something that has no operational benefit whatsoever.
If they start publishing type 99, something will break, because when
you change something in large systems, something always breaks. Some
mail systems somewhere with bugs in type 99 handling that they never
noticed will start making mail fail. For doing that, will anyone's
mail work better? No. Will their DNS work better? No.
As I have mentioned a couple of times already, even though Yahoo
doesn't publish SPF (I believe due to political issues related to the
history of Domainkeys and DKIM), they do check SPF. They used to
check both TXT and type 99, and stopped checking type 99. What
argumment is there to spend money to revisit and reverse that
decision?
Arguments about DNS purity, and hypothetical arguments about other TXT
records that will never exist are unlikely to be persusasive.
R's,
John