I ran into this issue many years ago, and I eventually gave up trying to increase the reputation of my mail server. For all my projects that require mailing, I'

I ran into this issue many years ago, and I eventually gave up trying to increase the reputation of my mail server. For all my projects that require mailing, I've now succumbed to spoofing headers using Gmail's SMTP, which surprisingly doesn't go to spam, or using a third party mailing service like AWS.