[witrak]

>> What matters is domain age, IP, and compliance with DKIM/DMARC.

>Maybe it was my IP, but I cycled a few with my hosting provider and none of them made a difference. If I am unable to reliable obtain a 'trusted' IP, what good does it do?

That's true. I have a Class C IP range and a domain registered for 30 years and yet Gmail still started ignoring my email server a couple of years ago...