mail.rogerstelecom.net has no CNAME records.
Question and response
Question
dig mail.rogerstelecom.net. NS
Answer
The response has no answer records.
Authority
rogerstelecom.net. 6961 SOA pub1-master1-iblox-wlfdle.mgmt.net.rogers.com. hostmaster.rogerstelecom.net. 1599624820 3600 1200 604801 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0