DKIM, DMARC, SPF, rDNS/PTR, EHLO... all correct and verified in the email "original source," BY GOOGLE. Still goes to SPAM folder because **** you, apparently. I hate Google.
Yeah, I figure I did enough of a step by moving to Tutanota. Selfhosting email seems like overkill unless you're running some large organization or doing self-hosting as a hobby.