> You self-host things that are easily self-hostable.
Exactly, which is why you can self-host e-mail, as there are turnkey packages available for that. Self-hosting e-mail does generate some extra workload, but that's atypical, and has to do with a) somewhat arcane tech that's underpinning e-mail, and b) whether it works or not with a wider ecosystem depends a lot on where you're self-hosting it. That b) in particular is not something you encounter elsewhere.
As for error reporting... I'm gonna risk asking: what's the challenge making it hard to self-host?
Email is only difficult to self host because it was intentionally corrupted by the major players using bad responses to spam as an excuse and now you need to stay in their good books to send.