exchange.spacecom.cz has no CNAME records.
Question and response
Question
dig exchange.spacecom.cz. NS
Answer
The response has no answer records.
Authority
spacecom.cz. 3368 SOA ns1.regzone.cz. administrator.czechia.cz. 2026030202 10800 1800 1814400 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0