mailrelay.kabelbw.com has no MX records.
Question and response
Question
dig mailrelay.kabelbw.com. MX
Answer
The response has no answer records.
Authority
kabelbw.com. 7200 SOA ns1.vodafone-ip.de. hostmaster.adm.arcor.net. 2023012400 28800 14400 1814400 7200
Additional
. 0 OPT ; payload 1460, xrcode 0, version 0, flags 0