You’re welcome. Stay safe!

I think you’re in luck here. You can use XMPP or Matrix as the other person said, and pick from the myriad of different servers to let the authorities play whack-a-mole with them. If you’re picking XMPP, suggest them one of the clients that support OMEMO (it uses the protocol used by Signal too; edit: most apps that support it are modern and in active development). Briar is another good option, since it uses Tor, but you both need to be online in order to receive messages from each other since it uses no servers (unless they and you use something like this on a spare phone).

An option that would likely be a better fit for what you’re looking for, but which I haven’t tried yet is SimpleX.

Whatever you pick, I think it would be a great practice for you to teach them to use a panic button app such as Ripple (not sure if that’s maintained anymore though).

Hmmm, that’s true. Probably OP checked this, but now that you mentioned it, I would do the same 😁

What happens with ordinary email by the way?

I expect it was previously appealing based on the fact that only the vendor had access (of course, now it no longer applies).

Maybe another option is to use one of the private providers that do not track you and are less mainstream than Proton. Let’s say Tuta or Mailbox.org (if they are not blocked already too). Probably encrypt the emails with PGP too for more security.

Tbh I’d probably use snail mail letters for anything private on the theory that the RU govt doesn’t have the resources to open all the envelopes

Hahahaha!

I’m not a Russian, rather Romanian. But I heard stories how all the mail coming from the outside was checked and “vetted for anything suspicious” at the border during communism. Since we and USSR were on the same team I suppose they did the same. And how the way the public institutions work barely changed, nowadays, given the current situation, I expect them to return to that practice.

So yeah, I wouldn’t trust snail mail with anything sensitive.

XMPP is more niche but on the other side more established. It has been used by both Facebook (now Meta), Google and WhatsApp (now part of Meta) to develop their platforms on. Up until recently you could still communicate with someone on Hangouts through an XMPP client, despite only with someone that was also on Hangouts (that was until they pulled the plug on that app). It didn’t support all the features but hey, it was there.

XMPP does have some modern clients too, but indeed, Matrix has been more designed with the 2020s in mind.