mail.bcc.com.uz has no CNAME records.
Question and response
Question
dig mail.bcc.com.uz. NS
Answer
The response has no answer records.
Authority
bcc.com.uz. 7891 SOA ns1.bcc.com.uz. hostmaster.bcc.com.uz. 2020082067 10800 1800 2419200 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0