smtp01.oderland.net has no CNAME records.
Question and response
Question
dig smtp01.oderland.net. NS
Answer
The response has no answer records.
Authority
oderland.net. 300 SOA ns.oderland.net. registry.oderland.se. 2026020602 10800 3600 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0