Apex domains cannot have CNAME records.
Question and response
Question
dig createsend.com. NS
Answer
createsend.com. 5 NS ns3.createsend.com.
createsend.com. 5 NS ns2.createsend.com.
createsend.com. 5 NS ns5.createsend.com.
createsend.com. 5 NS ns0.createsend.com.
createsend.com. 5 NS ns1.createsend.com.
createsend.com. 5 NS ns4.createsend.com.
Authority
The response has no authority records.
Additional
ns0.createsend.com. 5 A 208.94.148.133
ns1.createsend.com. 5 A 208.80.124.133
ns2.createsend.com. 5 A 208.80.126.133
ns3.createsend.com. 5 A 208.80.125.133
ns4.createsend.com. 5 A 208.80.127.133
ns5.createsend.com. 5 A 208.94.149.133
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0