v4.dfn.nl has no MX records.
Question and response
Question
dig v4.dfn.nl. MX
Answer
The response has no answer records.
Authority
v4.dfn.nl. 3600 SOA ns1.dfn.nl. hostmaster.dfn.nl. 2026021901 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0