posman.maxserver.co.id has no MX records.
Question and response
Question
dig posman.maxserver.co.id. MX
Answer
The response has no answer records.
Authority
maxserver.co.id. 1800 SOA dora.ns.cloudflare.com. dns.cloudflare.com. 2396399604 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0