mail.knalogvn.com has no CNAME records.
Question and response
Question
dig mail.knalogvn.com. NS
Answer
The response has no answer records.
Authority
knalogvn.com. 2559 SOA nsbak.pavietnam.net. hostmaster.knalogvn.com. 2025120210 14400 3600 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0