I send mail from Digital Ocean. I can tell you that neither Apple nor Microsoft give two hoots about any of those if you are on their ASN blocklist.

I send lots of email that is verified with SPF and DKIM to them via relays. But any messages sent directly from "untrustworthy" IP ranges are just blocked with a generic message.

This is in contrast to GMail which rightfully treated my first messages as suspicious. But once a handful of users pressed "not spam" they don't care about what IP it comes from anymore as the ___domain reputation has taken precedence.

Not only that. I used to run an email server and despite the fact that I had all of that one day outlook decided to consider my IP address (on AWS EC2) as spam and thus reject emails.

To this day is too much effort running your email service. I moved to an account to Infomaniak that works good and I don't dove all my data to Microsoft or Google.

Well, yeah.

That's why I meant the above as table stakes. They are the cost to even get in the game to get punched with bullshit IP reputation lists.

But if one doesn't have even PTR records, one has no leg to stand on complaining about blocklists.