spf.spamhero.com CNAME records

CNAME Canonical name
Apex domains cannot have CNAME records.

Question and response

Question

dig spf.spamhero.com. NS

Answer

spf.spamhero.com. 5 NS ns2.dnsbox.net. spf.spamhero.com. 5 NS ns.dnsbox.net.

Authority

The response has no authority records.

Additional

ns.dnsbox.net. 5 A 208.53.48.154 ns2.dnsbox.net. 5 A 45.79.100.232 . 0 OPT ; payload 1232, xrcode 0, version 0, flags 0