Apex domains cannot have CNAME records.
Question and response
Question
dig paradocmail.co. NS
Answer
paradocmail.co. 4 NS matias.ns.cloudflare.com.
paradocmail.co. 4 NS dora.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0