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Apple iCloud Mail is a sleek, user-friendly webmail service integrated into Apple's ecosystem. It offers seamless synchronization across Apple devices, robust spam filtering, and generous storage options, making it an ideal choice for Apple users seeking a streamlined email experience.

Proton Mail is a privacy-focused email service that prioritizes security and user confidentiality. With end-to-end encryption, zero-access encryption, and Swiss privacy law protection, it offers a secure communication platform for over 70 million users across web and mobile platforms.

Zimbra is an enterprise-grade, open-source email and collaboration platform. It offers a feature-rich webmail interface, calendaring, file sharing, and team collaboration tools. With both cloud and on-premises deployment options, Zimbra provides a flexible and scalable solution for organizations of all sizes.

Outlook Web App is a comprehensive web-based information management suite by Microsoft. It features a robust email client, intuitive calendar tools, contact management, and task organization capabilities. Its seamless integration with other Microsoft services makes it a popular choice for businesses and individuals alike.