eu52-emailsignatures-cloud.codetwo.com has no CNAME records.
Question and response
Question
dig eu52-emailsignatures-cloud.codetwo.com. NS
Answer
The response has no answer records.
Authority
codetwo.com. 180 SOA ns10.digicertdns.com. dns.digicertdns.com. 2009010523 43200 3600 1209600 180
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0