mxgate.melbourneit.com.au has no CNAME records.
Question and response
Question
dig mxgate.melbourneit.com.au. NS
Answer
The response has no answer records.
Authority
melbourneit.com.au. 167 SOA meg.ns.cloudflare.com. dns.cloudflare.com. 2396981382 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0