spf.lionhead.nl has no MX records.
Question and response
Question
dig spf.lionhead.nl. MX
Answer
The response has no answer records.
Authority
lionhead.nl. 3600 SOA ns1.lionhead.nl. annelies.lionhead.nl. 1770809908 10800 3600 604800 10800
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0