mail.enforta.com has no CNAME records.
Question and response
Question
dig mail.enforta.com. NS
Answer
The response has no answer records.
Authority
enforta.com. 2668 SOA ns8.ertelecom.ru. noc.ertelecom.ru. 2026030200 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0