ip4-mel-au.hostedmail.net.au has no MX records.
Question and response
Question
dig ip4-mel-au.hostedmail.net.au. MX
Answer
The response has no answer records.
Authority
hostedmail.net.au. 86400 SOA ns1.corp.ventraip.net.au. servers.vip-servers.com. 2022080708 86400 7200 3600000 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0