I'd just rather pay someone a small monthly/annual fee to do it for me, along with keeping my data private.
The idea is that the server is yours, and yours only. We manage the setup, monitoring, alarms and all the boring stuff. If you need any assistance, we have sysadmins that can help for a fee, and depending on how critical it is for you, we'd offer multiple levels of subscription with different service levels and response times.
You mention response times and priority support, and are talking about choosing nginx vs Apache. That's far more detail than I care about. I want to click a button, give you my card details, have an inbox and calendar that I can easily access on my phone, work machine and home machine, and with some level of guarantee about the security and privacy of my data. I'm not bothered about support response times - 99.9% of the time I'm not going to need it.
I want google mail + Google calendar, without the Google.
The listed roles were just to show the idea of the service; an role providing mail and calendar (e.g. Kolab) would only have a few required options (if any). Any additional detail would be optional and have our default recommended values.
[1]https://apps.sandstorm.io/app/8kr4rvyrggvzfvc160htzdt4u5rfvj...
As an aside, after this article I wanted to give Fastmail a shot, but I had already signed up a while ago and then never logged back in. I asked support if they could give me another trial so I could actually try it out, but they said I had to pay. Not great customer support there, especially since I had sent or received zero emails and creating another account for a trial is trivial...
I'd like the European level of the data privacy but also a company that is set to live long, and the web site looks too much like a startup that can disappear tomorrow (as in "it didn't grow enough, who cares, it's just a web address, let's kill it and do something else.")
Edit: Not saying it's modern or user friendly. It has worked for me for 10 years without touching it, though.