ms3.dempseyclark.eu has no MX records.
Question and response
Question
dig ms3.dempseyclark.eu. MX
Answer
The response has no answer records.
Authority
dempseyclark.eu. 86400 SOA ns1.dacc.cz. domains.dacc.cz. 2018060902 14400 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0