After a number of amateurish attempts at setting up a personal e-mail server over the years, I ended up resorting to running a poste (https://poste.io) docker container, which has worked great so far.

But I found the section about SPF/DKIM/MARC still very useful, and wish there were even more information about this. Testing whether e-mail is sendable or receivable is pretty easy. Understanding these scores is much harder (presumably because, if this were easily testable, it would also be easily gameable).