mail.conova.com has no CNAME records.
Question and response
Question
dig mail.conova.com. NS
Answer
The response has no answer records.
Authority
conova.com. 561 SOA adns001.dc1.conova.com. domainadmin.conova.com. 2026022006 10800 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0