exsmtp4.enbridgegas.com has no NS records.
NS records for this zone are defined at enbridgegas.com.
NS records for this zone are defined at enbridgegas.com.
Question and response
Question
dig exsmtp4.enbridgegas.com. NS
Answer
The response has no answer records.
Authority
enbridgegas.com. 1800 SOA blue.foundationdns.com. webpresence.enbridge.com. 2399324367 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0