[dns-operations] about list's MX

Paul Vixie paul at redbarn.org
Mon May 26 02:39:56 UTC 2014

hua peng wrote:
> ...
> $ dig lists.dns-oarc.net mx
> # got a CNAME
> If no MX provided, how will the messages be routed?

this example demonstrates the nature of CNAME, which is non-type-specific.

the smtp client will try lists.dns-oarc.net/mx and get a CNAME but zero
answers, so it will try /aaaa and get a CNAME with zero answers, so it
will try a /a and get CNAME with an answer. thus RFC 974 (MX) is
independent of RFC 1035 (CNAME).

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