mx3.dataline.ua has no CNAME records.
Question and response
Question
dig mx3.dataline.ua. NS
Answer
The response has no answer records.
Authority
dataline.ua. 2302 SOA ns.dataline.ua. hostmaster.dataline.ua. 2022111001 3600 900 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0