smtp2.coceve.com has no NS records.
NS records for this zone are defined at coceve.com.
NS records for this zone are defined at coceve.com.
Question and response
Question
dig sf2.coceve.com. NS
Answer
The response has no answer records.
Authority
coceve.com. 900 SOA ns-1695.awsdns-19.co.uk. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0