backup-mx.easynet.be has no CNAME records.
Question and response
Question
dig backup-mx.easynet.be. NS
Answer
The response has no answer records.
Authority
easynet.be. 1768 SOA ns1.gtt.net. hostmaster.gtt.net. 2026030501 10800 3600 3600000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0