It's not an issue to run your own server. I have several email servers for my company in our own datacenter. The issue is keeping your email server off of blacklists. This is easy when you just send a few emails for e.g. a small company, but as soon as you start sending thousands of emails, others will start blacklisting you since you appear to be a spammer, especially when some of your emails get flagged as such - by accident or otherwise - by some of the the tens of thousands of users of the forum.
I was not referring to Will or any individual. I'm saying this is a problem created by corporations that (a) moved everyone to cloud providers and then (b) cloud providers that put spam that isn't really spam on those lists (often because they don't comply with corporate created "standards") then (c) reject emails and punish IPs for those lists and (d) have created a hosting environment that punishes people hosting servers on those IPs.
Blacklists overall are not necessarily a bad thing. But, look at how many issues are created in a large corporate controlled system. The point I'm making is that if the big corporations did not interfere with the evolution of the Internet, EVERYONE would be running their own email servers. Wouldn't have to do anything. Could be default for any OS install. If you are concerned about uptime, you can put one in a VPS that forwards to yours, or rent one like that (which is also one way to host one in your home and get around port blocking). Email should be P2P. So, if people want to whitelist any sender, by domain, email address or IP, they can. Centralization is our current problem.
What can individuals do today? They can begin by not taking port blocking lying down. Demand an ISP that does not block port 25. You might have to pay for business, but if we all paid for business, there would either be no consumer/business tiers, or they would have to stop port blocking the consumer tier to preserve the more profitable multi-tier pricing. The competition of ISPs at the end of the day would evolve to demand. But, people are not demanding it.
Look at the original problem. People are clicking on the SPAM button on emails from the forum. Those individuals likely aren't trying to blacklist. They have no idea that the corporate email system they are using is doing more than just putting those emails in the Trash bin. They may even think that the Trash bin is a convient way to have those kinds of emails deleted in 30 days.
Likewise, if everyone had their own email server, they can decide which blacklists to use. In the end, we'd vote for the best of breed, or just quit using them. I personally quit using them because I found better ways to block spam using methods you can only do if you run your own email server. (If you run a server, learn how to wildcard and change it to anything other than "+").
Where is the option to provide +1 info to these blacklists so when the +1 is greater than the SPAM clicks it can keep the forum sender off the blacklists? P2P solutions solve problems like this. Corporate solutions don't care about their impact.