m1.cartstack.com has no NS records.
NS records for this zone are defined at cartstack.com.
NS records for this zone are defined at cartstack.com.
Question and response
Question
dig m1.cartstack.com. NS
Answer
The response has no answer records.
Authority
cartstack.com. 900 SOA ns-301.awsdns-37.com. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0