mx1.workd.go.th has no NS records.
NS records for this zone are defined at workd.go.th.
NS records for this zone are defined at workd.go.th.
Question and response
Question
dig mx1.workd.go.th. NS
Answer
The response has no answer records.
Authority
workd.go.th. 1800 SOA amber.ns.cloudflare.com. dns.cloudflare.com. 2397905709 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0