dns.ksc.co.th has no MX records.
Question and response
Question
dig dns.ksc.co.th. MX
Answer
The response has no answer records.
Authority
ksc.co.th. 3600 SOA ns.ksc.co.th. hostmaster.ns.ksc.co.th. 2025073101 21600 900 604800 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0