Apex domains cannot have CNAME records.
Question and response
Question
dig vali.email. NS
Answer
vali.email. 5 NS ns-951.awsdns-54.net.
vali.email. 5 NS ns-1331.awsdns-38.org.
vali.email. 5 NS ns-1942.awsdns-50.co.uk.
vali.email. 5 NS ns-245.awsdns-30.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0