Some weeks ago, I’ve come across Delta Chat, whose main thing is “(near) instant messaging using your email”
That left me thinking, has this been attempted before? If not, why? Also, why (besides servers’ limitations as means to fight spam) isn’t this solution used more often, given that e-mail has been a decentralized solution for well over 40 years now?
I think things have gotten better.
A few weeks ago I set up my own email server using https://mail-in-a-box.email and it wasn’t so bad. Above the capabilities of most internet users, yes. It has helpful status checks to let you know what parts of the config you need to address or fix in order to get it working and delivering email. It took me a few hours to get everything working well.