MX_TARGET_IS_CNAME

warning

One of this domain's mail exchanges is an alias rather than a host; most senders follow it and some refuse, which looks like an intermittent fault.

Working today, and one change away from not working.

How we know

mx.test
The same records are correct or broken depending on what the domain is for: nomail is a deliberate null MX, and the only difference between the passing and failing cases is what the caller says the domain does. Also carries the exchanges that cannot receive anything — an address written where a name belongs, an alias RFC 2181 forbids, a name with no address — plus an IPv6-only exchange, which is legitimate and would be failed by a check that reads a missing A record as a missing address.