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?
Back in the early 2000s, I was in a mailing list for a hobbyist group which was basically that. There was a central mailer client and we’d post to that central email address, and it would send it to everyone on the list. You could get a live feed, daily, or weekly mailings of everyone’s comments in mail threads.
I think these all went away with vBulletin and WordPress and all of that. That way you could search posts and didn’t have to archive it yourself, back when email storage was not unlimited.