vmd100528.contaboserver.net has no MX records.
Question and response
Question
dig vmd100528.contaboserver.net. MX
Answer
The response has no answer records.
Authority
contaboserver.net. 3600 SOA ns1.contabo.net. hostmaster.contabo.de. 1772255784 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0