regdns1.de has no MX records.
Question and response
Question
dig regdns1.de. MX
Answer
The response has no answer records.
Authority
regdns1.de. 600 SOA anycast.regdns1.de. hostmaster.internetwire.de. 2019022801 28800 7200 604800 600
Additional
. 0 OPT ; payload 1400, xrcode 0, version 0, flags 0