mail03.ml.odhserver.com has no CNAME records.
Question and response
Question
dig mail03.ml.odhserver.com. NS
Answer
The response has no answer records.
Authority
ml.odhserver.com. 3471 SOA ns01.odhserver.com. suporte.optidatacloud.com. 2026010106 3600 3600 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0