ns1.klfree.cz has no MX records.
Question and response
Question
dig ns1.klfree.cz. MX
Answer
The response has no answer records.
Authority
klfree.cz. 14400 SOA ns1.klfree.cz. root.klfree.net. 1772673596 10800 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0