mail.sitiapp.com has no NS records.
NS records for this zone are defined at sitiapp.com.
NS records for this zone are defined at sitiapp.com.
Question and response
Question
dig mail.sitiapp.com. NS
Answer
The response has no answer records.
Authority
sitiapp.com. 600 SOA ns23.domaincontrol.com. dns.jomax.net. 2026020301 28800 7200 604800 600
Additional
. 0 OPT ; payload 1280, xrcode 0, version 0, flags 0