In order to access the Kerio Control Web interface using only HTTPS, HTTP Strict Transport Security (HSTS) should be implemented on Kerio Control.
- Login to Kerio Control web interface as an Administrator.
- Go to Configuration > Advanced Options > Web Interface.
- Check the box
Force SSL secured connection (recommended).
Kerio Control web interface will be accessible only using it's HTTPS URL. It will not load with the HTTP URL.
If the website appears as Not Secure on the browsers, it may be because you are using a self-signed certificate and it will be necessary to request a certificate signed by a Certification Authority and use it for Kerio Control.