Apex domains cannot have CNAME records.
Question and response
Question
dig xsend1.email. NS
Answer
xsend1.email. 5 NS ns-344.awsdns-43.com.
xsend1.email. 5 NS ns-1254.awsdns-28.org.
xsend1.email. 5 NS ns-694.awsdns-22.net.
xsend1.email. 5 NS ns-1705.awsdns-21.co.uk.
Authority
The response has no authority records.
Additional
ns-344.awsdns-43.com. 1 A 205.251.193.88
ns-694.awsdns-22.net. 1 A 205.251.194.182
ns-1254.awsdns-28.org. 1 A 205.251.196.230
ns-1705.awsdns-21.co.uk. 1 A 205.251.198.169
ns-344.awsdns-43.com. 1 AAAA 2600:9000:5301:5800:0:0:0:1
ns-694.awsdns-22.net. 1 AAAA 2600:9000:5302:b600:0:0:0:1
ns-1254.awsdns-28.org. 1 AAAA 2600:9000:5304:e600:0:0:0:1
ns-1705.awsdns-21.co.uk. 1 AAAA 2600:9000:5306:a900:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0