Apex domains cannot have CNAME records.
Question and response
Question
dig enterprisemail.in. NS
Answer
enterprisemail.in. 3 NS ns2.enterprisemail.in.
enterprisemail.in. 3 NS ns1.enterprisemail.in.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0