mx.kolumbus.fi has no CNAME records.
Question and response
Question
dig mx.kolumbus.fi. NS
Answer
The response has no answer records.
Authority
kolumbus.fi. 3600 SOA ns-fi.elisa.net. hostmaster.elisa.fi. 2026012013 3600 900 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0