sender.vinmail.io has no NS records.
NS records for this zone are defined at vinmail.io.
NS records for this zone are defined at vinmail.io.
Question and response
Question
dig sender.vinmail.io. NS
Answer
The response has no answer records.
Authority
vinmail.io. 1800 SOA aron.ns.cloudflare.com. dns.cloudflare.com. 2397393707 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0