spf.servicemail24.de has no MX records.
Question and response
Question
dig spf.servicemail24.de. MX
Answer
The response has no answer records.
Authority
servicemail24.de. 3600 SOA dns009.arvato-systems.de. hostmaster.bnic.bertelsmann.de. 2026021100 3600 1800 3600000 3600
Additional
. 0 OPT ; payload 1680, xrcode 0, version 0, flags 0