v5202.v576a36ee.use4.send.mailgun.net has no NS records.
NS records for this zone are defined at v576a36ee.use4.send.mailgun.net.
NS records for this zone are defined at v576a36ee.use4.send.mailgun.net.
Question and response
Question
dig v5202.v576a36ee.use4.send.mailgun.net. NS
Answer
The response has no answer records.
Authority
v576a36ee.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