Apex domains cannot have CNAME records.
Question and response
Question
dig v6send.net. NS
Answer
v6send.net. 4 NS ns-1269.awsdns-30.org.
v6send.net. 4 NS ns-74.awsdns-09.com.
v6send.net. 4 NS ns-535.awsdns-02.net.
v6send.net. 4 NS ns-1833.awsdns-37.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0