smtp.capnova.com has no CNAME records.
Question and response
Question
dig smtp.capnova.com. NS
Answer
The response has no answer records.
Authority
capnova.com. 2082 SOA ns1.capnova.com. hostmaster.capnova.com. 2025071102 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0