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.
Good for you if you have a grandfathered account, but Sendgrid has a terrible interface. Setting up things is so messed up!
Again, not an endorsement, but Qboxmail is nice and EU-based.