To be clear, you’re talking about an outgoing mail server. An incoming mail server is pretty trivial to self-host and provides most of the benefits of self-host

To be clear, you’re talking about an outgoing mail server. An incoming mail server is pretty trivial to self-host and provides most of the benefits of self-hosting mail. The distinction is often lost in these discussions, which scares off a lot of people who in reality would have no trouble running their own MX.