Kontact Alternatives for Mac OS X

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.

Postbox is a powerful and customizable email client designed for professionals managing high volumes of email. It offers robust features for organizing, searching, and managing multiple accounts efficiently, enhancing productivity through a clean interface and advanced tools.

Apple Calendar is a personal calendar application developed by Apple Inc., designed to seamlessly integrate with your Apple ecosystem whether you are on macOS or iOS. It allows you to manage your schedule, appointments, and events efficiently, synchronizing across all your devices.

Rainlendar is a highly customizable calendar application for Windows, macOS, and Linux. It seamlessly integrates with popular online calendars like Google Calendar and Fantastical, offering comprehensive event and task management directly on your desktop.

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.

Sylpheed is a free and open-source email and news client known for its lightweight design and speed, focusing on usability and efficient handling of large email collections without burdening system resources.

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.

Fantastical is a powerful and intuitive calendar and task management application designed for macOS, iOS, and watchOS. Known for its natural language processing engine and elegant interface, it simplifies scheduling and staying organized across all your Apple devices.

Zimbra Desktop provides a unified interface for managing multiple email accounts, calendars, tasks, and contacts offline. It supports various protocols like IMAP, POP, CalDAV, and CardDAV, offering a comprehensive personal information management solution.

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.

Memotoo is a comprehensive online service designed to centralize and synchronize all your personal information, including contacts, calendars, tasks, notes, and bookmarks. It acts as a hub to connect various online services and devices, ensuring your data is consistent and accessible from anywhere.

Contacts is a fundamental contact management application designed for macOS, providing seamless integration within the Apple ecosystem for organizing and managing personal and professional connections.

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>