mx10.dhub.RU has no CNAME records.
Question and response
Question
dig mx10.dhub.RU. NS
Answer
The response has no answer records.
Authority
dhub.RU. 3417 SOA ns3.dhub.RU. administrator.dhub.RU. 357 900 600 86400 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0