Aerion has quickly become the preferred email client for Linux users, replacing Geary due to its clean, user-friendly interface and lightweight design. Developed by 3DF, a Hong Kong-based IT consultancy, Aerion is an open-source application that prioritizes privacy and efficiency. It supports a wide range of email services, including Gmail, Outlook, and ProtonMail Bridge, while offering essential features such as rich-text message formatting, email filtering, and a focus mode that enhances user experience. The application is designed for easy navigation, featuring a modern layout that includes an account pane, email list, and a viewing pane. Users can manage multiple email accounts seamlessly. Aerion is available for Linux, MacOS, and Windows, with installation on Linux requiring Flatpak. Despite being in pre-release, it has garnered positive feedback for its stability and functionality, making it a strong contender in the Linux email client market.