Self-hosted email is the hardest it's ever been, but also the easiest
Postfix and dovecot are not some evil "oligopoly", they're community based truly open source software.Almost none of the things linked there are run by serious isps that are responsible for other peoples' mail in quantities of tens of thousands of inboxes or more.Resist the urge to reinvent the wheel just to be a contrarian.Edit: yes, I see the issue, the mention of postfix+dovecot is jammed together in the same small paragraph as the oligopoly. It's as if they are being discussed as the same thing. The oligopoly is clearly google, office 365, etc. One hundred percent in agreement there.