ProtonMail Unofficial is a Firefox extension designed to enhance the functionality of ProtonMail by providing seamless notifications and session management. This subscription-based tool allows users to manage their email experience more efficiently by enabling features such as session persistence, which maintains user login even after closing the browser. It also offers customizable settings for checking new emails and displaying unread counts directly on the extension icon.

Key features include the ability to receive notifications for new emails, a peek function to view unread messages, and the option to save session information either temporarily or permanently. The extension directly interacts with official ProtonMail domains, ensuring secure and reliable access to email services. Overall, this extension enhances the usability of ProtonMail, making it a valuable addition for users seeking improved email management.