0.mail.carrierops.com has no MX records.
Question and response
Question
dig 0.mail.carrierops.com. MX
Answer
The response has no answer records.
Authority
carrierops.com. 3600 SOA ns1.subrigo.net. support.cloudns.net. 2025082102 7200 1800 1209600 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0