The use of the DKIM l=, z= and x= features provide a means for
recipients to separately evaluate DKIM signatures without reliance on
intermediary assessors. In addition, the A-R header does not capture
the IP address when assessing path registration protocols, which means
that safe recipient reassessment might only be possible in the case of
DKIM or reverse DNS.
[...]
Could we please not re-re-re-rehash these A-R issues on ietf-dkim? They were
already covered on mail-vet-discuss more times than I can count. The archives
of that list are public in case anyone really needs to go through them all
again.
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