The "guess" heuristic could be codified by specifying a default record
for checkers to use when no SPF record is published. This would correctly
handle the vast majority of domains, and for those where it doesn't do the
right thing - they only need to publish a record. Even if it is only
"v=spf1 ?all". Hopefully, this would motivate sysadmins to do the trivial
work of adding the SPF record. It is less trivial to add SRS, but they
can use ?all until they get around to it.
--
Stuart D. Gathman <stuart(_at_)bmsi(_dot_)com>
Business Management Systems Inc. Phone: 703 591-0911 Fax: 703 591-6154
"Very few of our customers are going to have a pure Unix
or pure Windows environment." - Dennis Oldroyd, Microsoft Corporation