mail.dace.be has no CNAME records.
Question and response
Question
dig mail.dace.be. NS
Answer
The response has no answer records.
Authority
dace.be. 32507 SOA ns.zxcs.be. hostmaster.dace.be. 2025102540 600 3600 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0