mail.managed-vps.net has no CNAME records.
Question and response
Question
dig mail.managed-vps.net. NS
Answer
The response has no answer records.
Authority
managed-vps.net. 10800 SOA ns1.managed-vps.net. admin.managed-vps.net. 2026022739 86400 7200 3600000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0