mail.uaprom.net has no CNAME records.
Question and response
Question
dig mail.uaprom.net. NS
Answer
The response has no answer records.
Authority
uaprom.net. 1085 SOA ns.promdns.net. noc.uaprom.net. 2951253567 43200 7200 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0