vmail-1.0rbitel.net has no NS records.
NS records for this zone are defined at 0rbitel.net.
NS records for this zone are defined at 0rbitel.net.
Question and response
Question
dig vmail-1.0rbitel.net. NS
Answer
The response has no answer records.
Authority
0rbitel.net. 86400 SOA ns.0rbitel.net. root.orbitel.bg. 2018010401 10800 3600 3600000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0