When I setup my server, roundcube wasn't available as a standard part of the perfect-install, so I still have squirrelmail. Now that I've upgraded to U16, I would like to install RoundCube, but since I run my own mail server, I would like to read about what needs to be done before I jump into it. I've searched the tutorials here, but haven't been able to find much info on how to do this with Ubuntu 16, postfix, dovecot, etc. Could some please post a link that discusses how to set it up using postfix/dovecot? I am still using ISPConfig 126.96.36.199p8 as I've made numerous changes to my install and implemented my own Let's Encrypt module (before it was officially included into ISPConfig). I will upgrade to the latest version sometime soon, but not just yet.