mx.postal.oderland.com has no CNAME records.
Question and response
Question
dig mx.postal.oderland.com. NS
Answer
The response has no answer records.
Authority
oderland.com. 600 SOA ns.oderland.net. registry.oderland.se. 2026021925 14400 86400 3600000 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0