smtp.tele.fi has no CNAME records.
Question and response
Question
dig smtp.tele.fi. NS
Answer
The response has no answer records.
Authority
tele.fi. 1947 SOA namesurfer.inet.fi. hostmaster.telia.fi. 2024050315 28800 7200 3456000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0