mail.sendmarc.net has no NS records.
NS records for this zone are defined at sendmarc.net.
NS records for this zone are defined at sendmarc.net.
Question and response
Question
dig mail.sendmarc.net. NS
Answer
The response has no answer records.
Authority
sendmarc.net. 1800 SOA kipp.ns.cloudflare.com. dns.cloudflare.com. 2397592078 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0