dns4.de has no MX records.
Question and response
Question
dig dns4.de. MX
Answer
The response has no answer records.
Authority
dns4.de. 3600 SOA anycast.regdns1.de. hostmaster.partnergate.de. 2025042202 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1400, xrcode 0, version 0, flags 0