mx001.cloudus.rs.oxcs.net has no CNAME records.
Question and response
Question
dig mx001.cloudus.rs.oxcs.net. NS
Answer
The response has no answer records.
Authority
oxcs.net. 300 SOA dns1.easydns.com. zone.easydns.com. 1771956097 3600 600 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0