I set up my own mail server for my own use at home. I did everything correctly: DNS, reverse DNS, DMARC, DKIM, SPF, etc. I have the best possible reputation score everywhere. I am the sole owner and user of the IP. But Gmail's magic sauce blocks me because apparently I'm not allowed to send a few emails a week to my own Gmail address from a residential IP... This situation caused by a duopoly that forces us to use either Gmail or 365 is truly a problem that only a regulator can fix.