srv.ldp.net.id has no MX records.
Question and response
Question
dig srv.ldp.net.id. MX
Answer
The response has no answer records.
Authority
ldp.net.id. 3600 SOA ns1.ldp.net.id. hostmaster.ldp.net.id. 2026020201 3600 900 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0