Apex domains cannot have CNAME records.
Question and response
Question
dig afinz-email.com.br. NS
Answer
afinz-email.com.br. 5 NS ns-1127.awsdns-12.org.
afinz-email.com.br. 5 NS ns-1951.awsdns-51.co.uk.
afinz-email.com.br. 5 NS ns-372.awsdns-46.com.
afinz-email.com.br. 5 NS ns-1005.awsdns-61.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0