firstwave-mx1.firstcloudsecurity.net has no CNAME records.
Question and response
Question
dig firstwave-mx1.firstcloudsecurity.net. NS
Answer
The response has no answer records.
Authority
firstcloudsecurity.net. 96 SOA ns1.firstwave.com.au. admin.firstwave.com.au. 2017030224 3600 600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0