OnionShare is available for Android.

:) Thank you. Yes Mail in a box has been around for a while. Still not straightforward, though.

Hehe You answered your own statement! If it were ever to become non-trivial : I’d certainly do it (even though I know people who do, are bombarded with spam).

Yes… I guess if someone were to only use Tox, the device they were using it on would have to be on all the time, with one of the Tox clients running at least in the background.

Addendum At least you know when the other person is online… There’s some advantage to that.

They’re kept on other people’s servers, is what I meant.

I’ve wondered before now about an e-mail system which hosts the emails on one’s own device, and uses the activity-pub protocol : decentralised email, I guess…

The closest I’ve seen is Tox.