kabel-deutschland.de has no MX records.
Question and response
Question
dig kabel-deutschland.de. MX
Answer
The response has no answer records.
Authority
kabel-deutschland.de. 3600 SOA ns01.registrar.kabel-deutschland.de. dns-admin.kabeldeutschland.de. 2025072271 10800 7200 604800 86400
Additional
. 0 OPT ; payload 1680, xrcode 0, version 0, flags 0