mx2.opusnet.com has no CNAME records.
Question and response
Question
dig mx2.opusnet.com. NS
Answer
The response has no answer records.
Authority
opusnet.com. 354 SOA ns1.opusinteractive.io. sysadmin.opusinteractive.com. 2026012201 5400 600 1209600 5400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0