mail7.infosecmail.net has no NS records.
NS records for this zone are defined at infosecmail.net.
NS records for this zone are defined at infosecmail.net.
Question and response
Question
dig mail7.infosecmail.net. NS
Answer
The response has no answer records.
Authority
infosecmail.net. 900 SOA ns-2018.awsdns-60.co.uk. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0