mx.ispeg.eu has no CNAME records.
Question and response
Question
dig mx.ispeg.eu. NS
Answer
The response has no answer records.
Authority
ispeg.eu. 10748 SOA ns1.ispeg.eu. hostmaster.ispeg.eu. 202505150 86400 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0