mx-filter-proxy.ispservices.us has no CNAME records.
Question and response
Question
dig mx-filter-proxy.ispservices.us. NS
Answer
The response has no answer records.
Authority
ispservices.us. 60 SOA ns1.ispservices.us. hostmaster.ispservices.us. 2025120301 3600 600 1209600 60
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0