Email.biz Alternatives for Windows

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

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.

Claws Mail is a powerful yet lightweight, open-source email and news client built on GTK+. It's known for its speed, stability, rich feature set, and high degree of customization, making it an excellent choice for users demanding control and efficiency.

The Bat! is a secure and powerful email client for Windows designed for users who prioritize privacy, speed, and efficient email management, especially for handling large mail volumes.

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.

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.

Kontact is a comprehensive personal information management suite from KDE combining email, contacts, calendar, tasks, and news in one integrated application. It offers robust synchronization options and supports various protocols.

Mailvelope is a free and open-source browser extension for Chrome and Firefox that brings end-to-end encryption to your existing webmail services using the OpenPGP standard. It allows users to encrypt, decrypt, and digitally sign emails directly within their web browser, enhancing privacy and security without requiring a change in email provider.

Microsoft Mail and Calendar is the default email and calendar client included with Windows, providing integrated tools to manage your communications and schedule.