Avoiding RBL with droplet mail server

I’m hosting Postfix/Dovecot mail servers with another company. Because this other company has random bad actors who abuse services, their class-C IP blocks are frequently on block lists. This creates a huge hassle for me, as some of these entities absolutely will not unblock one or more IPs in huge blocks - with or without ransom fees.

I’m considering moving my servers and all domains to DO droplets, but concerned about the exact same issues. Sure, these companies do what they can to keep off of RBLs, but in the meantime we have users who can’t send or receive email.

As an example, we haven’t been able to directly exchange email with any Microsoft Office 365 users for months, because Microsoft and their clients subscribe to fringe RBLs that hold entire class C blocks hostage for months at a time. We have no control over this, and it’s too easy for it to happen randomly and repeatedly.

All of our sites are for our own small privately owned businesses. We do not offer mail service subscriptions. There are no unknown entities using these servers. There is never any UCE/spam sent from these servers, no bulk mail that can be perceived as spam, and thus, no reason, ever, to be on a RBL.

Not running our own servers is not an option. We use tooling for management of DNS, sites, mail, users, security, and other features common to an ISP. We have many domains, but a small number of human users, and the common costs of per-user / per-domain email services is prohibitive. We’re all subject to RBLs and other issues when we pay any company for email services, so pushing the problem to someone else isn’t a solution - we came from that, not going back.

Does DigitalOcean have a reserved block of floating IPs that are curated to stay off of RBLs?

What other policies/services does DO have to help us avoid this same fate?

What else can we do to avoid these problems if hosting with DO?

Note: I asked a similar question two years ago and got no response. :(

Thanks!