ns4.melbourneit.net has no MX records.
Question and response
Question
dig ns4.melbourneit.net. MX
Answer
The response has no answer records.
Authority
melbourneit.net. 3600 SOA ns1.mysecurecloudhost.com. admin.melbourneit.net. 2026020304 86400 7200 3600000 172800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0