mx.glb.proximus.be has no MX records.
Question and response
Question
dig mx.glb.proximus.be. MX
Answer
The response has no answer records.
Authority
glb.proximus.be. 300 SOA dfonegamgtm2.glb.proximus.be. hostmaster.dfonegamgtm2.glb.proximus.be. 2025071503 10800 3600 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0