Sylpheed is a free, open-source, lightweight email and news client for Windows, Mac, Linux, and other Unix-like operating systems. It features an intuitive, user-friendly interface, support for multiple accounts, and a powerful filtering system. With Sylpheed, users can easily manage their emails, search for messages, create filters to automatically sort incoming messages, and more. Additionally, Sylpheed can be integrated with other applications, such as Claws Mail, GPG, and more. It also allows users to customize the look and feel of the application with themes and plugins. Sylpheed is a great choice for those looking for a lightweight, feature-rich email client.
The discontinued Opera Mail is no longer updated and is no longer supported, but the latest version, 1.0.1044, released in February 2016, can still be downloaded from the official website.