mail.spoje.net has no CNAME records.
Question and response
Question
dig mail.spoje.net. NS
Answer
The response has no answer records.
Authority
spoje.net. 2989 SOA ns.spoje.net. tech.spoje.net. 1772215304 3600 600 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0