mail.arp.edu.do has no NS records.
NS records for this zone are defined at arp.edu.do.
NS records for this zone are defined at arp.edu.do.
Question and response
Question
dig mail.arp.edu.do. NS
Answer
The response has no answer records.
Authority
arp.edu.do. 300 SOA ns1.bluehost.com. root.box2173.bluehost.com. 2025040400 86400 7200 3600000 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0