Anyways, my point was not to suggest a full solution but to say that companies are not incentivized to solve this problem.
Yes it is. Besides just syncing the data there are a huge number of other performance hits.
> of course you don't need to store the attachments etc.
Why not? Do you want to a) drop support for searching through attachments (like pdfs) or b) not encrypt those?
> companies are not incentivized to solve this problem.
There has been huge improvements in the last few years in this space (take Signal as an example). But major email providers are not incentivized because most users don't care, UX and performance suffer, email is inherently an unsafe (even if you put PGP on top [1]) and because they would not be able to make as much ad revenue (worse targeting).
