Earlier quoted context omitted.
They couldn't. They would have to show ads from other history and not the email's contents. This would also break features such as (server-side) search and reminders (eg. flight tomorrow) via Google Now. End-to-end is a tradeoff. But presumably they wouldn't be working on the technology if they weren't prepared to offer it in some fashion. Probably as an opt-in? Hopefully a Googler can offer more insight as I can onl…
>They couldn't. They would have to show ads from other history and not the email's contents. This would also break features such as (server-side) search and reminders (eg. flight tomorrow) via Google Now. Sure they could, all incoming emails aren't magically going to become e2e encrypted.
If the goal is to make E2E more accessible then eventually more emails will come in encrypted. Maybe Google will let users with the extension find each other, or Gmail might help coordinate that.