You can now choose to encrypt your stored mail with a key only you hold, and use OpenPGP for end-to-end encrypted messages. The encrypted mailbox is opt-in: turn it on, or off again, under security.
encrypted mailbox: your stored mail and search index are encrypted with a mailbox key that only you hold.
it works on the regular site, the no-JavaScript site, Tor and I2P.
we cannot recover that key. if you lose it, the mail encrypted with it is gone.
you can turn it off again: it asks for your account number, second factor, mailbox key and a typed confirmation, sends you an alert, and stores your mail readable again.
while it's on, moving mail needs your mailbox unlocked, snooze is unavailable, and mail apps that use app passwords can't read your mail.
OpenPGP on the regular site: messages are encrypted and decrypted in your browser.
OpenPGP on the no-JavaScript site: decrypt on our server for a single page view (clearly labelled), or paste text you encrypted yourself.
you can export your OpenPGP private key.
public keys are published for primary addresses only. aliases are never linked to them.
an offline decryption tool: one file you download and open locally. it makes no network requests.