Open Source Alternatives to Proton Mail

A secure email provider that uses end-to-end and zero-access encryption to protect user privacy. The service prevents the provider from accessing user data and blocks email trackers to stop third-party monitoring. It is designed for individuals, journalists, activists, and businesses seeking private communication. The platform is headquartered in Switzerland and provides open-source apps for web, desktop, Android, and iPhone. Capabilities include custom email domains, hide-my-email aliases, and password protection for messages. Users can also connect Gmail accounts to send and receive emails from a single secure inbox. It is deployed as a cloud-based service accessible via web browsers or dedicated applications. The service is funded by paying subscribers to avoid the use of surveillance-based business models. All Proton services are open source and independently audited for security.

Whether you want to cut software costs or escape vendor lock-in, these open source alternatives to Proton Mail give you an option you fully own. You can self-host them, so your data stays on infrastructure you control. This page lists 1 open source alternative to Proton Mail. The most popular is Tuta. It uses the GPL-3.0 license.