No, there is no definitive solution.
Let's say you use a mail server with some host and their address is 123.456.789.001. Some group/company maintaining a block list might get a report that spam is coming from 123.456.789.201. They decide to black-list the entire group of IPs: 123.456.789.* (001-254). All domains on all servers and all of their users now have services interrupted, perhaps for one spammer on one domain on one server. And the spam report might have been bad. Some idiot user might have registered to get email from a company and then when they got email in their AOL or Yahoo browser they might have clicked it as spam, intentionally or accidentally. With a few of these the RBLs take action. Your site could be blocked because some idiots out there hit the wrong button on email that nothing to do with you.
And yes, this happens with all email service providers. And you can't host your own email server and avoid the problem because you can't control what some other company says about your IP address.
I said earlier "This is what we get for depending on 30 year old protocols for modern critical business needs". What I meant there is that the email protocols we use today were devised 30 years ago and little has changed since. We spend billions of dollars in patches and anti-malware and RBLs to avoid problems stemming from the use of the old protocols, rather than migrating to a completely new system that should avoid the problems. It's insanity on a global scale but everyone accepts it as though there is no solution.
That said, a company like DreamHost is now big enough to raise a voice in their industry to eliminate some of the insanity, but I'm sure (a) their marketing people aren't aware of how this might work in their favor, and (b) until they can see a way to draw some revenue from a new initiative they're not inclined to even discuss the matter.
OK DreamHost, here's the message you need to convey to the the world:
- To RBL maintainers: We own this block of mail servers and we will police it mercilessly. Every RBL needs to keep our block off of their list. Period. If you get a report related to our block, send it to us and we'll take care of it.
- To mail server developers: In addition to running RBLs, allow servers to maintain a white list of IPs that never get blocked by any RBLs. Add DH servers to that list.
- To DH customers: We have zero tolerance for spam. If you are caught with verified spam from our servers, we will not only remove you from our service but we'll black list you through your credit card company so that no other host will sell you a domain, sell you web hosting services, or sell you email services. You will be banned from using the internet by any legitimate hosting company, and companies that ignores this list will eventually learn to stop providing services to you.
- To anyone who uses email (the multi-billion dollar prospect base of companies and individuals worldwide who need services) you can rely on us to keep your email flowing because we've taken pro-active steps to make that happen - and we want your business.
I don't think that will go anywhere, but if anyone at DH has cajones to strike out for some new revenue or at least to make a huge marketing splash, that's a vector to do it.
Until then, no, there's nowhere to hide, at least with IPv4. With IPv6 everyone on the planet may get an IP address and we can address spam at an individual level. But that's just another world-shaking radical approach...