ns2.xenox-systems.net has no MX records.
Question and response
Question
dig ns2.xenox-systems.net. MX
Answer
The response has no answer records.
Authority
xenox-systems.net. 86400 SOA ns1.first-ns.de. dns.hetzner.com. 2025050904 86400 10800 3600000 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0