php84.gxzone.com has no MX records.
Question and response
Question
dig php84.gxzone.com. MX
Answer
The response has no answer records.
Authority
gxzone.com. 1800 SOA wanda.ns.cloudflare.com. dns.cloudflare.com. 2396529941 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0