Mailspring Alternatives for Windows

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.

Mailbird is a powerful and intuitive desktop email client for Windows, designed to streamline your email workflow and centralize your digital communication with a clean interface and built-in app integrations.

eM Client is a comprehensive email client for Windows and macOS, integrating email, calendar, contacts, tasks, and chat into a single application. It offers robust features for managing multiple accounts, advanced security options, and a user-friendly interface, making it a powerful alternative to other popular email applications.

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.

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.

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.

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.

Spike transforms your inbox into a collaborative workspace, merging email, chat, calls, and documents into a single, streamlined interface. It redefines communication by making email more conversational and integrates project management tools, file sharing, and calendar functionality to boost productivity for individuals and teams, aiming to be a true all-in-one productivity hub.