Open Domino Server Certificate Administration (CERTSRV.NSF). This is in the System Databases in the administration panel of Notes.
Choose Install Trusted Root Certificate into Key Ring.
Enter the file name of the key ring (it was made when you created CSR file).
Install the Trusted Root Certificate (TrustedRoot.crt).
Note: If you receive message that the root certificate is already installed – continue to next step.
Again choose Install Trusted Root Certificate into Key Ring.
Enter the file name of the key ring, then install your Intermediate Certificate(s).
Note: If your zip file includes DigiCertCA2.crt, install that file first, and then repeat this process to this same location with DigiCertCA.crt. Otherwise, you only need to install the DigiCertCA.crt file here.
Choose Install Certificate into Key Ring.
Enter the file name of the Key Ring and install Primary Certificate (your_domain_name.crt) using the Merge Certificate into Key Ring button.
Your SSL Certificate has been installed.