On Fri, 27 Aug 2004, Jim Lyon wrote:
On Friday, August 27, 2004 at 3:10 PM, David Blacka writes:
Why not:
SHOULD publish SPF2
MAY publish TXT
MUST publish at least one of the two.
Because if you publish an SPF2 record without a TXT record, those of us
who can't query for an SPF2 record will conclude that you didn't publish
anything.
That is why we should have a MUST for looking up SPF RR record. Its
been shown (including with Microsoft products) that grabbing arbitrary
data type in dns (including new data type by its number) can be done
using existing low-level dns libraries. Its true that these "uknown"
data types can not be interpreted by the library and will be just
a binary data but for the SPF data format that is exactly what
is needed and its up to the client to interpret it. So in my view
there is no reason why we should NOT have clients be REQUIRED to lookup
up new SPF RR records. But its additional matter that if they don't get
the answer they may want to lookup TXT.
--
William Leibzon
Elan Networks
william(_at_)elan(_dot_)net