mail.anyvm.tech has no CNAME records.
Question and response
Question
dig mail.anyvm.tech. NS
Answer
The response has no answer records.
Authority
anyvm.tech. 1001 SOA annalise.ns.cloudflare.com. dns.cloudflare.com. 2397989855 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0