mail3.orbitel.bg has no CNAME records.
Question and response
Question
dig mail3.orbitel.bg. NS
Answer
The response has no answer records.
Authority
orbitel.bg. 600 SOA ns.orbitel.bg. root.orbitel.bg. 2025082501 10800 3600 3600000 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0