To install your certificate, you need either the .zip file that you received in your email from VikingCloud or you can download it within the VikingCloud Control Center. The .PEM file in the .zip file contains the "PEM Concatenated" certificate and the intermediate certificate. Once you have downloaded it, return to the Web Admin interface. Click "SSL Certificates Configure" and then go to the area where you originally created your CSR.
In the "SSL Certificate(s)" field, you will need to paste your entire PEM concatenated certificate from VikingCloud. To do so, open your PEM concatenated certificate file and copy the entire file from top to bottom. Paste this data right into the "SSL Certificate(s)" field in the SurgeMail WebAdmin.
Press Save and then restart SurgeMail. Your new certificate will be working as soon as SurgeMail restarts.