rgsmtp.madgeniuses.net has no NS records.
NS records for this zone are defined at madgeniuses.net.
NS records for this zone are defined at madgeniuses.net.
Question and response
Question
dig rgsmtp.madgeniuses.net. NS
Answer
The response has no answer records.
Authority
madgeniuses.net. 900 SOA ns-1667.awsdns-16.co.uk. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0