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?
Guessing here, but probably because it’s extremely difficult in the modern day to host your own email server; you’d be depending on one of the big/established players to handle the traffic.
I’ve run my own email since ~2013 or so, and if I had to set it up from scratch today, I probably wouldn’t. There’s just so many hoops to jump through to get it going, secure it properly, and get your messages accepted by the big players. Not to mention, getting a clean IPv4 address from a VPS provider that isn’t on every spam block list is damn near impossible. With some work, you can clean those up, but Microsoft has some internal block lists that are extremely difficult to get removed from (there’s a form you can fill out, but good luck finding it). I’d guess other big players have similar “internal” block lists. With those, the email doesn’t bounce or give any indication there was a delivery failure, it just silently goes into a black hole: the sending server assumes it’s accepted, and the recipient never sees it.
Also, most residential connections flat-out block outgoing SMTP on port 25, so self-hosting would not be possible for many.
If an email-based chat/IM platform were to eschew compatibility with existing email services and just used the protocols on different ports, it may be feasible, but it would have to run in parallel to other email services or rely on some kind of “bridge” setup (probably not what those projects are going for).
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.
Congrats. Even with an “in a box” solution, getting email up and running is no small feat. I went with a classic Postfix+Dovecot+Spamd+ClamAV setup. Has worked well for me but definitely isn’t for the faint of heart lol. I spent forever trying to get DKIM working correctly only to realize that my DNS provider was accepting the DKIM TXT record in full, but was internally truncating it to 255 characters. Some DNS providers will automatically split it into multiple records transparently or if not, reject it for being too long; mine didn’t lol, and showed the full record in the control panel but only served the first 255 characters. Had to manually split it myself, and it worked after that.
The biggest issue I had was cleaning up the IP address of the VPS that was hosting it. I setup two, actually. The first one was easy since I was the first to be assigned that IP, and I only had to remove it from Microsoft’s hidden, internal block list. The second one, my backup MX, was more of a challenge as I set it up a few years later, and the assigned IP had been around the block a few times and was on every spam list imaginable.
Once it was up and running, and without it being a source of spam, it’s been pretty easy to maintain. But getting to that point was challenging.