E2E is supported for specific types of folders available only to teams but the admin has to enable it and that folder has to be used. You can't apply it team wide to all users. It's a very poor implementation.
If you want E2E, encrypt your data yourself. By far the simplest, safest solution to the problem.
If you want E2E, encrypt your data yourself. By far the simplest, safest solution to the problem.