relay.zoner.com has no MX records.
Question and response
Question
dig relay.zoner.com. MX
Answer
The response has no answer records.
Authority
zoner.com. 3600 SOA ns1.regzone.cz. administrator.czechia.cz. 2026022204 10800 1800 1814400 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0