Inbox by Gmail 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.

Mailpile is a free and open-source webmail client designed with privacy and encryption as core principles. It offers a self-hostable solution for managing your email with built-in support for PGP encryption and other security features, providing an alternative to traditional webmail services.

Mailspring is a modern, fast, and free desktop email client for Mac, Windows, and Linux. It offers a beautiful interface, powerful features like unified inbox, email tracking, and broad platform support for an enhanced email experience.

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.

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.