a.xnameserver.de has no MX records.
Question and response
Question
dig a.xnameserver.de. MX
Answer
The response has no answer records.
Authority
xnameserver.de. 3600 SOA a.xnameserver.de. hostmaster.xnameserver.de. 2022062902 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1400, xrcode 0, version 0, flags 0