mx02.ek-hosting.net has no MX records.
Question and response
Question
dig mx02.whitelabelserver.nl. MX
Answer
The response has no answer records.
Authority
whitelabelserver.nl. 3600 SOA ns1.whitelabelserver.nl. hostmaster.whitelabelserver.nl. 2026021200 3600 3600 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0