Apex domains cannot have CNAME records.
Question and response
Question
dig squalomail.com. NS
Answer
squalomail.com. 5 NS ns1.itars.eu.
squalomail.com. 5 NS ns2.itars.eu.
Authority
The response has no authority records.
Additional
ns1.itars.eu. 5 A 5.157.72.1
ns2.itars.eu. 5 A 91.185.193.219
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0