maildev.exactbid.com has no NS records.
NS records for this zone are defined at exactbid.com.
NS records for this zone are defined at exactbid.com.
Question and response
Question
dig maildev.exactbid.com. NS
Answer
The response has no answer records.
Authority
exactbid.com. 900 SOA ns-885.awsdns-46.net. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0