ns4.edpnet.be has no MX records.
Question and response
Question
dig ns4.edpnet.be. MX
Answer
The response has no answer records.
Authority
edpnet.be. 600 SOA ns1.edpnet.be. admin.edpnet.be. 2026012300 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0