mailer.sendings.email has no NS records.
NS records for this zone are defined at sendings.email.
NS records for this zone are defined at sendings.email.
Question and response
Question
dig mailer.sendings.email. NS
Answer
The response has no answer records.
Authority
sendings.email. 600 SOA ns13.domaincontrol.com. dns.jomax.net. 2017072700 28800 7200 604800 600
Additional
. 0 OPT ; payload 1280, xrcode 0, version 0, flags 0