ns2.start-dns.de has no MX records.
Question and response
Question
dig ns2.start-dns.de. MX
Answer
The response has no answer records.
Authority
start-dns.de. 360 SOA ns1.start-dns.de. support.partner4trade.de. 2023060101 14400 3600 604800 360
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0