I'm forging ahead trying to create my own cloud services, as will hopefully be covered in the new TekLinux channel with @wendell Super EXCITED :-D
Starting with a Debian 8 install on Linode, I decided the first thing I wanted was my own email server and decided on using RoundCube. In their installation guide, they have a tutorial on creating the "Perfect Server" which has gone fine for the first 13 of the 20 steps, but installing Quota in Step 14 has got me scratching my head.
The likely problem, as discussed on this HowToForge Trhead, is that I'm running it on a virtual machine.
I think I'm actually going to back pedal and go with YunoHost for now, so I don't really need a solution. Though since it's a topic that may come up for others following along in the future, I thought I'd post it somewhere.