Reading your mail on a computer or phone

Your mail is read and written in Private.Ki's own software — the web app in any browser, or the app on your phone — because that is where the key that decrypts your mailbox lives. There is no POP3 or IMAP access and no SMTP login.

You can:

• use the web app in any modern desktop or mobile browser — see Web app vs. native app;
• install the apps on your phone;
• receive mail from anyone and send to anyone. SMTP is how our server talks to the rest of the world; it is only the login for you that does not exist.

Why

Your mailbox is stored as ciphertext for your key. Every message — including mail that arrived from outside in clear — is encrypted to your PGP key the moment it reaches our server, and the private key exists only on your devices, protected by your passphrase. A mail client speaking IMAP would receive the stored ciphertext, which it has no key to open — encrypted subjects, no sender names.

There is no password on the server to log in with. Private.Ki authenticates you with the OPAQUE protocol: the server never sees your passphrase, not even during sign-in, and it holds nothing a password could be checked against. IMAP, POP3 and SMTP authentication all work by sending a password to the server. There is nothing on our side for such a login to compare against, and building one would mean storing something we have deliberately chosen never to store.

The security marks live in the app. The padlocks, the signature check, blocked images, the link confirmation, the sender's key import, the key-change warning — all of it runs in Private.Ki's own code on your device, after decryption. A third-party client would either skip these checks or, with PGP add-ons, do them in its own way and with its own keys. The guarantees described in this help centre would no longer hold.

Sending goes through the composer for a reason. Encryption for each recipient, signing, the check that every external recipient has a key, and the header handling that keeps your device out of the message are done on your device and finished by our server. A generic SMTP relay would have to accept whatever a client sends, in clear.

If you need mail in a desktop program

The Private.Ki web app runs in a desktop browser with the full mail and chat feature set, keyboard shortcuts included, and can be pinned as its own window in most browsers (Install app or Add to Dock in the browser menu). Attachments download to your computer like any other file, and Show original lets you save any received external message as a standard .eml file that mail programs can open.

What our server sees

Common questions