mail.cpanelhosting.rs has no CNAME records.
Question and response
Question
dig mail.cpanelhosting.rs. NS
Answer
The response has no answer records.
Authority
cpanelhosting.rs. 443 SOA dns1.sbb.rs. hostmaster.eunet.co.rs. 2025112600 21600 300 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0