mx.ecentry.com has no CNAME records.
Question and response
Question
dig mx.ecentry.com. NS
Answer
The response has no answer records.
Authority
ecentry.com. 3600 SOA ns.ecentry.com. sysadmin.ecentry.com. 2024071505 10800 86400 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0