"as long as it's clearly marked as ephemeral" - yep, you hit the nail on the head there. The ecosystem danger is that ephemeral becomes the default. Who doesn

"as long as it's clearly marked as ephemeral" - yep, you hit the nail on the head there. The ecosystem danger is that ephemeral becomes the default. Who doesn't love the ability to silently fix mistakes. And when it becomes the cultural norm to send editable email, then people will do it because it's a nice experience as a sender if you have the choice. I sure enjoy being able to edit my posts on HN when I get something wrong. I'd love to be able to take back and "fix" emails that I've sent too! But having to stand by exactly what you sent when it comes to email is really a valuable part of how email works. If you made a mistake, you send a correction, but the recipient still has your original mistake too. They don't see it, then have it disappear when they go back to look at it again.