esainternal.MAILSECURE.IN has no CNAME records.
Question and response
Question
dig esainternal.MAILSECURE.IN. NS
Answer
The response has no answer records.
Authority
MAILSECURE.IN. 10800 SOA dns1.tatacommunicationsdns.com. root.dns5.tatacommunicationsdns.com. 2025102905 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0