_spf.deutschepost.de has no MX records.
Question and response
Question
dig _spf.deutschepost.de. MX
Answer
The response has no answer records.
Authority
deutschepost.de. 600 SOA ns.deutschepost.de. postmaster.deutschepost.de. 2026011303 14400 7200 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0