mail4216.mkt4813.com has no NS records.
NS records for this zone are defined at mkt4813.com.
NS records for this zone are defined at mkt4813.com.
Question and response
Question
dig mail4216.mkt4813.com. NS
Answer
The response has no answer records.
Authority
mkt4813.com. 900 SOA ns1.acoustic-adm.com. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0