mail.octo.uz has no CNAME records.
Question and response
Question
dig mail.octo.uz. NS
Answer
The response has no answer records.
Authority
octo.uz. 4667 SOA dns1.webspace.uz. root.dns1.webspace.uz. 2026022000 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0