mail.thermoking-bg.com has no MX records.
Question and response
Question
dig mail.thermoking-bg.com. MX
Answer
The response has no answer records.
Authority
thermoking-bg.com. 86400 SOA ns1.s8.r1servers.com. office.hostbulgaria.com. 2026030202 86400 7200 3600000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0