mx.ncnet.ru has no CNAME records.
Question and response
Question
dig mx.ncnet.ru. NS
Answer
The response has no answer records.
Authority
ncnet.ru. 483 SOA nsmt.rt.ru. hostmasternsmt.rt.ru. 2020122400 86400 7200 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0