mx.readingsbyrevmarcus.com has no NS records.
NS records for this zone are defined at readingsbyrevmarcus.com.
NS records for this zone are defined at readingsbyrevmarcus.com.
Question and response
Question
dig mx.readingsbyrevmarcus.com. NS
Answer
The response has no answer records.
Authority
readingsbyrevmarcus.com. 3600 SOA dns.readingsbyrevmarcus.com. hostmaster.readingsbyrevmarcus.com. 1834129850 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0