@email@example.com @bob@kev@uwehermann@avndp IMO, Signal app should be in every phone capable. No it's not ideal, but at least it claims to encrypt everything ETE, and it's just as easy to use as the default text message and audio/video options. It's cross-platform iMessage.
@firstname.lastname@example.org @bob@kev@uwehermann@avndp I should clarify that this would be the starting point. I think this is the quickest win for maximizing the number of people using envelopes rather that just sending postcards.