v5152.v5c112201.use4.send.mailgun.net has no NS records.
NS records for this zone are defined at v5c112201.use4.send.mailgun.net.
NS records for this zone are defined at v5c112201.use4.send.mailgun.net.
Question and response
Question
dig v5152.v5c112201.use4.send.mailgun.net. NS
Answer
The response has no answer records.
Authority
v5c112201.use4.send.mailgun.net. 300 SOA ns-cloud-e1.googledomains.com. cloud-dns-hostmaster.google.com. 1 21600 3600 259200 300
Additional
. 0 OPT ; payload 512, xrcode 0, version 0, flags 0