mail02.tks.co.th has no NS records.
NS records for this zone are defined at tks.co.th.
NS records for this zone are defined at tks.co.th.
Question and response
Question
dig mail02.tks.co.th. NS
Answer
The response has no answer records.
Authority
tks.co.th. 1800 SOA aria.ns.cloudflare.com. dns.cloudflare.com. 2398946152 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0