alerting.digitalkcloud.com has no CNAME records.
Question and response
Question
dig alerting.digitalkcloud.com. NS
Answer
The response has no answer records.
Authority
digitalkcloud.com. 5120 SOA ns0.digitalkcloud.com. admin.digitalkcloud.com. 1430411807 10800 3600 1209600 38400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0