> 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.

I get my IP through work, but another way of obtaining one would be subscribing to a business account with a regular ISP. Normally, this also allows you to set a reverse DNS. You will likely have to pay more for your Internet, but considering that you won't have to pay for any cloud service anymore, you will probably still come out ahead and gain a huge amount of sovereignty over your computing. A VPS could be an option, but many (cheap ones) may have tainted IPs or outright filter the SMTP port.