> You need a clean fixed IP in non-residential block

Feels like that's carrying a lot of load there?

Where do you get those? I doubt any inexpensive VPS provider has any clean IP addresses? AWS charge you $5/month for an elastic IP address, and I bet you'd need to cycle through their pool of those looking for one that hasn't been blacklisted recently?

There's another thing to consider here too. I was selfhosting my own mail, but back in 2013/14 I investigated all my mail, and even though I'd avoided Google/Microsoft,Yahoo et al. - over 80% of my personal email was on their servers because that's where my correspondents were. I pretty much gave up maintaining my own (slightly over complicated) stuff and gave in and chose to accept the "Do no evil" company at face value. 4 or 5 years later that company no longer existed, even though they continue with the same name today.