I’ve configured a server with DirectAdmin with a Letsencrypt certifcate. Everything works fine on Mac, Pc, iOS and Android: See https://www.letoservice.nl.
Now I tried to use the same certificate files for Exim by making a symlink from /etc/exim.cacert, /etc/exim.cert and /etc/exim.key to the letsencrypt certifcate elsewhere on the server.
On Windows live mail (Windows 10) and Apple Mail (Mac OS El Captain) SSL mail works great.
At my updated iphone the certificate isn’t trusted at all.
I asked a friend to check on his updated Android device and the certifcate isn’t trusted on that device either.
Has anyone else issued the same problem before? Did I misconfigured something or is Letsencrypt just not authorized yet?