Forgot one more useful page with client-side details: https://partofthething.com/thoughts/host-your-own-contacts-and-calendars-and... I hope that helps. There's a related discussion (related to the above) at Hacker News, that I consider mostly lame, but might have something useful or at least have entertainment value: https://news.ycombinator.com/item?id=14836265 At a quick glance, much of the traffic is either (1) people claiming their lives are so much simpler after they ceased trying to self-host their data and outsourced everything to $BIG_DUMB_FIRM, or (2) people singing the praises of baroquely overengineered things like ownCloud / NextCloud or SOGo. https://news.ycombinator.com/item?id=14836265 SOGo is medium-heavy-weight groupware (https://en.wikipedia.org/wiki/SOGo). ownCloud (open core) / NextCloud (open source) are public-facing PHP apps {shudder} with lots of JavaScript {bonus shudder}.