For your CA signed certificates to be trusted, you need to trust your Root certificate or CA if you don't use a Root certificate.

Download the Root 230RO.cer file

Windows

Start > certmgr Right click on Trusted Root Certification Authorities > All Tasks > Import... import import_1 import_2 Browse and select Trusted Root Certification Authorities import_3 import_4

Chrome / Edge

They use the Windows SSL store

Firefox / Thunderbird

Go to Settings and search for Manage certificates firefox firefox_import

Browse and select Root 230RO.cer

Trust this CA to identify web sites Trust this CA to identify email users

firefox_import_1

Linux