spf.ms5899.incert.at has no MX records.
Question and response
Question
dig spf.ms5899.incert.at. MX
Answer
The response has no answer records.
Authority
incert.at. 3600 SOA ns1.your-server.de. postmaster.your-server.de. 2026021001 14400 1800 604800 7200
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0