smtp08.enbridge.com has no CNAME records.
Question and response
Question
dig smtp08.enbridge.com. NS
Answer
The response has no answer records.
Authority
enbridge.com. 718 SOA blue.foundationdns.com. webpresence.enbridge.com. 2397854404 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0