mail.cloud4.mailernet.work has no CNAME records.
Question and response
Question
dig mail.cloud4.mailernet.work. NS
Answer
The response has no answer records.
Authority
cloud4.mailernet.work. 1800 SOA ns1.mailernet.work. secure757.mailernet.work. 2026010501 7200 3600 1209600 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0