You perfectly answered my question, thanks! You're fortunate to have a public IP at home. Many self-hosters need a VPS just for the public IP 👌 I had thought this was your case.

https://pubmed.ncbi.nlm.nih.gov/8262106/

mu4e+mbsync+msmtp

The ancestral high-protein diet: drinking the tears of your fallen enemies.

That could be very useful when using a text-based web browser (e.g. TUI)

I am not an expert, but I see that the Apache license has no copyleft.

I don't know about OP, but it is available in https://thecapslock.gitlab.io/fdroid-patched-apps/fdroid/repo and https://calyxos.gitlab.io/calyx-fdroid-repo/fdroid/repo

I have seen many different ways to achieve that in Emacs. Do you have one to recommend (modes, packages)? Do you synchronise calendars with other devices (e.g. smartphone, server)?

There is a payment option inside the app. It uses Stripe to process the payment.

There is also Element Call at call.element.io. I have not tried screen-sharing but it's worth a look.

obligatory xkcd

FairEmail is the best email app I've ever used.