Apex domains cannot have CNAME records.
Question and response
Question
dig email-protect.gosecure.net. NS
Answer
email-protect.gosecure.net. 5 NS ns-1723.awsdns-23.co.uk.
email-protect.gosecure.net. 5 NS ns-201.awsdns-25.com.
email-protect.gosecure.net. 5 NS ns-611.awsdns-12.net.
email-protect.gosecure.net. 5 NS ns-1466.awsdns-55.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0