mail.nbl.fi has no CNAME records.
Question and response
Question
dig mail.nbl.fi. NS
Answer
The response has no answer records.
Authority
nbl.fi. 1800 SOA namesurfer.inet.fi. hostmaster.telia.fi. 2024101015 1016333 600 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0