mail.arbibox.com has no NS records.
NS records for this zone are defined at arbibox.com.
NS records for this zone are defined at arbibox.com.
Question and response
Question
dig mail.arbibox.com. NS
Answer
The response has no answer records.
Authority
arbibox.com. 1800 SOA doug.ns.cloudflare.com. dns.cloudflare.com. 2396664797 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0