sms.gBLNET.ru has no CNAME records.
Question and response
Question
dig sms.gBLNET.ru. NS
Answer
The response has no answer records.
Authority
gBLNET.ru. 5295 SOA ns.gBLNET.ru. vvv.gBLNET.ru. 2026030201 10800 1200 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0