mail.optima-telekom.hr has no MX records.
Question and response
Question
dig mail.optima-telekom.hr. MX
Answer
The response has no answer records.
Authority
optima-telekom.hr. 120 SOA dns1.optima-telekom.hr. dns.optima-telekom.hr. 2025020502 86400 3600 2419200 172800
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0