After self-hosting my email for twenty-three years I have thrown in the towel. The oligopoly has won.

Email is now an oligopoly, a service gatekept by a few big companies which does not follow the principles of net neutrality. Many companies have been trying to disrupt email by making it proprietary. So far, they have failed. Email keeps being an open protocol. Email is not distributed anymore. You cannot set it up on your own datacenter.