It's my belief that DKIM selectors don't allow CNAME's. Am I correct?
Nope. A CNAME is just an indirect address. For example, this would work
with all the DNS implementations I know:
foo._domainkey.bar.com CNAME farble.baz.org
farble.baz.org TXT "normal dkim key record"
But as I said, CNAME loops have been a feature of the DNS for 25 years,
and we're not making the situation any worse. That's why Paul said
queries that return a record or something like that. CNAMEs are either an
infinite loop or a chain that terminates.
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