Zimbra Desktop Alternatives for Mac OS X

Thunderbird is a free, open-source email client developed by the Mozilla Foundation, offering robust features for managing multiple email accounts, integrated chat, and RSS feeds. Known for its extensibility and focus on user privacy and security.

Microsoft Outlook is a comprehensive personal information manager designed for managing email, contacts, calendars, and tasks.

Apple Mail is the default email client for macOS, iOS, and watchOS, offering a seamless and integrated email experience across Apple devices with features like rich text editing, multiple account support, and robust organization tools.

QupZilla is a free and open-source web browser designed for general users, emphasizing speed, privacy, and a clean user interface. It leverages the powerful QtWebEngine to deliver a modern browsing experience while remaining lightweight and resource-efficient.

Airmail is a powerful and lightning-fast email client designed for macOS and iOS. It aims to provide a clean, modern interface with advanced features for managing multiple email accounts efficiently.

Mutt is a highly configurable, text-based email client for Unix-like systems. It offers powerful features for advanced users who prefer a lightweight and efficient email management experience directly from the command line.

Iridium Browser is a security-focused web browser built upon the Chromium codebase. It prioritizes user privacy by significantly reducing data transmission to Google and other servers, while incorporating enhanced security features and utilizing the latest secure technologies for a safer browsing experience.

OpenProject is a powerful, web-based open-source project management software designed for teams of all sizes. It offers comprehensive tools for managing projects, tasks, teams, and communication in one centralized platform. Ideal for organizations prioritizing collaboration, flexibility, and data control.

KMail is a powerful and flexible email client tightly integrated with the Kontact personal information manager suite. Part of the KDE ecosystem, it offers robust features for managing your email, including strong encryption options, support for multiple protocols like IMAP, POP3, and Exchange, and seamless integration with other Kontact components like the calendar and address book.

Polymail is an advanced email client for macOS and iOS, built to enhance productivity for professionals using Gmail. It goes beyond basic email functions with robust features like email tracking, scheduling, and team collaboration tools, all wrapped in a sleek and intuitive interface.

<p>MailMate is a powerful, keyboard-centric IMAP email client for macOS designed for users who demand advanced email management capabilities and a highly customizable workflow, featuring strong Markdown integration and robust search features.</p>