v5248.v5994f88d.use4.send.mailgun.net has no NS records.
NS records for this zone are defined at v5994f88d.use4.send.mailgun.net.
NS records for this zone are defined at v5994f88d.use4.send.mailgun.net.
Question and response
Question
dig v5248.v5994f88d.use4.send.mailgun.net. NS
Answer
The response has no answer records.
Authority
v5994f88d.use4.send.mailgun.net. 300 SOA ns-cloud-a1.googledomains.com. cloud-dns-hostmaster.google.com. 1 21600 3600 259200 300
Additional
. 0 OPT ; payload 512, xrcode 0, version 0, flags 0