mailserver.pavietnam.com has no NS records.
NS records for this zone are defined at pavietnam.com.
NS records for this zone are defined at pavietnam.com.
Question and response
Question
dig mailserver.pavietnam.com. NS
Answer
The response has no answer records.
Authority
pavietnam.com. 3600 SOA dns1.pavietnam.com. admin.pavietnam.vn. 2026013000 3600 1800 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0