"Seth Goodman" <sethg(_at_)GoodmanAssociates(_dot_)com> writes:
I guess that would surprise me. Implementing a minimal subset of an XML
parser would deprive XML proponents of the extensibility that was the reason
for XML in the first place. If you're going to limit the extensibility of
XML, is there really any advantage over SPF syntax for the purpose at hand?
As has already been pointed out, such extensibility is not desirable
anyway. The email checking algorithm should be deterministic - so
that all compliant implementations should return the same result for
any given email.