smtp.telus.net has no CNAME records.
Question and response
Question
dig smtp.telus.net. NS
Answer
The response has no answer records.
Authority
telus.net. 2992 SOA dns24.telus.com. dnsadmin2.telus.com. 2018081064 900 7200 3600000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0