mx31.tanet.cz has no MX records.
Question and response
Question
dig mx31.tanet.cz. MX
Answer
The response has no answer records.
Authority
tanet.cz. 3600 SOA ns.wedos.net. wedos.wedos.com. 2026011401 3600 1800 1814400 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0