smtp.ofsys.com has no CNAME records.
Question and response
Question
dig smtp.ofsys.com. NS
Answer
The response has no answer records.
Authority
ofsys.com. 4 SOA ns-cloud-a1.googledomains.com. dns-admin.google.com. 0 21600 3600 1209600 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0