I run into a similar situation, and I have done every thing you are supposed to. DMARC, SPF, MTA-STS, DKIM, all of it. I have only one IP address that ever se

I run into a similar situation, and I have done every thing you are supposed to. DMARC, SPF, MTA-STS, DKIM, all of it. I have only one IP address that ever sends legitimate email from my domain (I proxy all my personal messages through that IP), on AWS, and it's been that way for years. Despite that, the reputation systems give my system a neutral reputation. Sure, I know that there are lots of people who spam through AWS, but AWS IPs are not allocated in bunches, and anyone can get one. There should be some way to get my reputation up to good, but I haven't yet figured it out.