ns3.createsend.com has no CNAME records.
Question and response
Question
dig ns3.createsend.com. NS
Answer
The response has no answer records.
Authority
createsend.com. 113 SOA ns10.digicertdns.com. dns.digicertdns.com. 2009010160 43200 3600 1209600 180
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0