Horde Groupware vs Proton Mail

Horde Groupware is a web-based collaboration platform that provides email, calendar, contacts, tasks, and notes in a single interface. It is built on the Horde PHP framework and can be self‑hosted on any standard web server. The suite supports IMAP/SMTP integration, shared calendars, and granular permission controls, making it suitable for organizations that need a customizable, privacy‑focused alternative to commercial groupware solutions.

Proton Mail is a secure, privacy-focused email service founded by CERN scientists and protected by strict Swiss privacy laws. It utilizes end-to-end encryption and zero-access encryption to ensure that even the provider cannot read user messages. The platform offers a seamless experience across web and mobile devices, featuring modern interfaces, custom domain support, and integrated calendar and drive services. Designed for individuals and organizations seeking ultimate data confidentiality, it removes ads and trackers from standard email workflows.

• Completely free and open-source
• Highly customizable via plugins
• Runs on standard LAMP environments
• Strong permission and sharing controls

• Strong Swiss legal protection and privacy jurisdiction
• Zero-access encryption means data cannot be handed over to third parties
• Ad-free experience with no tracking of user habits
• Open-source client apps audited by independent security experts

• Requires technical expertise to install and maintain
• User interface feels dated compared to modern SaaS tools
• Limited mobile app support; relies on web browser

• Free tier has strict storage limits and features disabled
• Metadata such as sender, recipient, and timestamps cannot be fully encrypted by email standards
• Paid subscription required for advanced features like custom domains and multiple addresses