mx1.jpberlin.de has no MX records.
Question and response
Question
dig mx1.jpberlin.de. MX
Answer
The response has no answer records.
Authority
jpberlin.de. 1800 SOA ns.jpberlin.de. root.jpberlin.de. 2014830889 14400 1800 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0