After years of self-signed certificates, I finally have valid, trusted SSL certificates for my domains thanks to Let’s Encrypt. Although still in beta, having the certificats issued worked flawlessly using the letsencrypt command line tool and the short instructions from the official documentation.
Now it’s no problem to access HTTP, CalDAV, email or other services on my server without being bugged by “invalid certificate” warnings or, in case of many mobile OS, needing to install a self-signed certificate manually on the client device.