Dave Crocker wrote:
Arvel Hathcock wrote:
I propose that the side advocating removal of the NXDOMAIN check agree
to language which makes this step AT LEAST a SHOULD and preferably a MUST.
Having the ADSP specification include normative text that calls for
validating
the From field domain name does two things:
1. Couples an entirely separate and more generally useful mechanism (checking
domain name validity) to one that is considerably more limited (ADSP).
2. Modifies SMTP. (Yes, really.)
This is a reason that we shouldn't reference a domain existence check in
a separate document (if one indeed exists). A separate description is
likely to be interpreted in a way that modifies SMTP, while the
description in ADSP simply returns the ADSP result, "the domain does not
exist." The specification is carefully non-normative what to do in this
case, and therefore does not modify SMTP.
Having non-normative text that describes it serves to promote the idea but
not
couple it with the fate of ADSP.
Having the ADSP result depend on non-normative language in this case
does not meet the bar of interoperability that we need to achieve.
Making it non-normative means that two spec-compliant implementations of
ADSP would return completely different results for non-existent domains.
-Jim
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