smtp.variomailprotection.net has no CNAME records.
Question and response
Question
dig smtp.variomailprotection.net. NS
Answer
The response has no answer records.
Authority
variomailprotection.net. 1800 SOA ns0.ambisys.jp. hostmaster.ambisys.com. 2025051501 10800 1800 3600000 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0