Enter the (available for Windows, macOS, and Linux). It isn't just a web page wrapped in a pretty frame. It is a standalone fortress for your email.
Free tiers have constrained storage parameters, meaning power users will eventually need to upgrade to handle large attachments.
When downloading new messages, the Bridge fetches the encrypted data from the cloud, decrypts it locally using your private key, and passes the plaintext to your chosen desktop client.
This is the killer feature. With the web version, if the Wi-Fi goes down, so does your email.