ns1.pldt.net has no MX records.
Question and response
Question
dig ns1.pldt.net. MX
Answer
The response has no answer records.
Authority
pldt.net. 86400 SOA ns1.pldt.net. root.ns1.pldt.net. 2014113592 3600 3600 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0