The ProtonMail Bridge application is available for paid users. Once you connect your ProtonMail account to ProtonMail Bridge application, you can access your email account from popular email clients. This application is available for Windows, Mac, and Linux.The ProtonMail Window's app runs in the background and encrypts the emails you send. Also, it decrypts the emails that you receive. This application is compatible with most email clients that support IMAP and SMTP.To know how to get the Protonmail windows app and encrypted mail, refer to the simple steps given on this page.