Scribe can be local, if that’s what you are referring to.

They also have a specific section on it at proton.me/…/proton-scribe-writing-assistant#local…

Also emails for the most part are not e2ee, they can’t be because the other party is not using encryption. They use “zero-access” which is different. It means proton gets the email in clear text, encrypts it with your public PGP key, deletes the original, and sends it to you.

See proton.me/…/proton-mail-encryption-explained

The email is encrypted in transit using TLS. It is then unencrypted and re-encrypted (by us) for storage on our servers using zero-access encryption. Once zero-access encryption has been applied, no-one except you can access emails stored on our servers (including us). It is not end-to-end encrypted, however, and might be accessible to the sender’s email service.