_spf.ndcx.cz has no MX records.
Question and response
Question
dig _spf.ndcx.cz. MX
Answer
The response has no answer records.
Authority
ndcx.cz. 3600 SOA ns.forpsi.net. admin.forpsi.com. 2026020101 14400 3600 2592000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0