mx1.mail.vrmd.de has no CNAME records.
Question and response
Question
dig mx1.mail.vrmd.de. NS
Answer
The response has no answer records.
Authority
vrmd.de. 10549 SOA ns1.variomedia.de. support.variomedia.de. 2025121858 28800 7200 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0