ms2.dempseyclark.cz has no MX records.
Question and response
Question
dig ms2.dempseyclark.cz. MX
Answer
The response has no answer records.
Authority
dempseyclark.cz. 86400 SOA ns1.dacc.cz. domains.dacc.cz. 2016110501 14400 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0