mx.mediaworks.rs has no CNAME records.
Question and response
Question
dig mx.mediaworks.rs. NS
Answer
The response has no answer records.
Authority
mediaworks.rs. 300 SOA ns1.mediaworksit.net. root.ns1.mediaworksit.net. 2024021202 10800 3600 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0