Any data that is collected on servers will eventually leak or be abused otherwise.

By design, no one can enumerate #deltachat profiles which are private and not published on any server. Conversely, #chatmail relays do not see or collect private data or metadata.

But wait, there is more :)

We are currently evolving end-to-end security protocols and UX to **survive an attacker fully taking over a server**. The attacker shall not even be able to message users, let alone impersonate anyone.