Since you are German, don´t forget the Impressum. I think it is mandatory and some people are dicks.

Thanks for pointing out Simplex Chat, I did not know that it exists. It looks very interesting, but reading more about it, they will have to implement some kind of business model in the future. My fear is, that even when self-hosting, some features will be behind a paywall in the future, so it is not a solution I would switch to… switching to a new messenger is a long-term endeavour. It is hard to convince friends to move over too, let alone switching to a new one every few years. That’s near impossible. But the technology of Simplex looks really interesting and reading through the Docs it makes the impression that it is very polished.

Thank you very much for the technical insight. It makes clear why it is how it is and it is good to see that you can host Activitypub services on Subdomains… so the issue I thought that exists is not that big of an issue anymore. Also I love the discussion under your post, very interesting!

Thanks also to everyone else who replied!