mta.ocrm3.pearson.com has no NS records.
NS records for this zone are defined at ocrm3.pearson.com.
NS records for this zone are defined at ocrm3.pearson.com.
Question and response
Question
dig mta.ocrm3.pearson.com. NS
Answer
The response has no answer records.
Authority
ocrm3.pearson.com. 900 SOA dns-emea-1.ptns.pearson.com. gns-dnsoperations.pearson.com. 55 900 900 2592000 900
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0