_05._spf.internet1.de has no MX records.
Question and response
Question
dig _05._spf.internet1.de. MX
Answer
The response has no answer records.
Authority
_spf.internet1.de. 86400 SOA ns.internet1.de. hostmaster.internet1.de. 2025091800 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0