The algorithm for when to delete could be very simple: 1) is expired? or 2) the client confirmed download.
Thinking of it as a shared account is likely wrong. Every device has its own place to check. Exchanging messages doesn’t have to mean direct connections. It doesn’t mean that for Signal.
The messages temporarily on the server can’t be read by the server, that’s the important difference. They also are not stored forever. The storage costs would grow forever that way.
The algorithm for when to delete could be very simple: 1) is expired? or 2) the client confirmed download.
Thinking of it as a shared account is likely wrong. Every device has its own place to check. Exchanging messages doesn’t have to mean direct connections. It doesn’t mean that for Signal.
The messages temporarily on the server can’t be read by the server, that’s the important difference. They also are not stored forever. The storage costs would grow forever that way.
@MacNCheezus