_spf.nederhost.net has no MX records.
Question and response
Question
dig _spf.nederhost.net. MX
Answer
The response has no answer records.
Authority
nederhost.net. 60 SOA ns1.nederhost.nl. hostmaster.nederhost.nl. 2026021901 86400 3600 604800 3600
Additional
. 0 OPT ; payload 1400, xrcode 0, version 0, flags 0