Even if you host your own email server, your emails are still handled by routers and the destination server unencrypted. You are not trusting others much less t

Even if you host your own email server, your emails are still handled by routers and the destination server unencrypted. You are not trusting others much less than not hosting your own email. If you have your own domain and you don't trust others with your conversations with others, I think you are better off hosting a chat server over an encrypted protocol, such as XMPP or IRC or https://blog.okturtles.com/2015/11/five-open-source-slack-alternatives/ https://blog.okturtles.com/2015/11/five-open-source-slack-al... . Persuading your contacts to use it is a problem though. Calendar is a different thing though. As long as you have a CalDAV server and a CalDAV client you should be good to go. Also related to selfhosting stuff: https://sandstorm.io/ https://sandstorm.io/ is a project I've discovered some time ago and haven't been paying attention to, but it seems to have thrived pretty well.