m4097.contaboserver.net has no MX records.
Question and response
Question
dig m4097.contaboserver.net. MX
Answer
The response has no answer records.
Authority
contaboserver.net. 3600 SOA ns1.contabo.net. hostmaster.contabo.de. 1771723652 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0