> From what I've gathered Amazon SES is a reliable alternative since they apparently jump through the hoops for you. That might be where I'm turning to for a solution.
Yes, definitely... at least for commercial sending. SendGrid, SES, Mailgun, Mailchimp - there are a lot of solutions for outbound commercial / bulk and they're reasonably priced and easy to use. They take care of all of the nuts and bolts.
For personal email, I started seeing this change a long time ago and stopped hosting my own at least ten years ago (around the time 1/2 of my DSL got consumed by spam bandwidth). At this juncture, I keep all of my domains on Gmail.
> Do you know why some emails are silently dropped while others are marked as junk and allowed to pass through?
Probably depends on spam score as to whether it gets bulk foldered or killed immediately, and the ISP.