gr.vpnunlimitedapp.com has no MX records.
Question and response
Question
dig gr.vpnunlimitedapp.com. MX
Answer
The response has no answer records.
Authority
vpnunlimitedapp.com. 1800 SOA hope.ns.cloudflare.com. dns.cloudflare.com. 2397090719 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0