Apex domains cannot have CNAME records.
Question and response
Question
dig debutmail.com. NS
Answer
debutmail.com. 5 NS blakely.debutmail.com.
debutmail.com. 5 NS otto.debutmail.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0