mx02.soverin.net has no CNAME records.
Question and response
Question
dig mx02.soverin.net. NS
Answer
The response has no answer records.
Authority
soverin.net. 3600 SOA ns1.premium-dns.net. hostmaster.soverin.net. 2026021901 86400 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0