The best open source alternative to Gmail is Proton Mail. If that doesn't suit you, our users have ranked more than 50 alternatives to Gmail and 18 is open source so hopefully you can find a suitable replacement. Other interesting open source alternatives to Gmail are Tuta Mail, Disroot, Posteo and Infomaniak kMail.
Proton Mail provides secure email services with end-to-end encryption, ensuring data protection. Swiss-based and outside US jurisdiction, it offers a free version to champion privacy as a human right. Fully accessible on any device.
Offers comprehensive encryption for email, calendar, and contacts with zero personal info required. Built on open source, install via Play Store, F-Droid, or APK, with Tor and VPN support. Both free and paid plans; utilizes quantum-resistant encryption ensuring privacy-focused, anonymous usage.
Disroot is a platform providing online services based on principles of freedom, privacy, federation and decentralization.
Web- and IMAP-based email service. 4GB cost 1€/month. Information is hosted on encrypted hard drives. Electricity from renewable resources is used.
Privacy-focused Swiss email system provides 20 GB free storage, supports custom domains and unlimited storage, syncs contacts and calendars, is ad-free, and is part of a secure productivity suite used by over a million users across Europe on all devices.
Forward Email is the best email service, encrypted email service, and fastest email service. It supports unlimited domains and aliases for no extra cost. It uses quantum safe ChaCha20-Poly1305 encryption and offers SMTP, IMAP, POP3, email webhooks, email regular expressions...
Zero is an open-source AI email solution that gives users the power to self-host their own email app while also integrating external services like Gmail and other email providers. Our goal is to modernize and improve emails through AI agents to truly modernize emails.
Galae is a secure email service focused on deliverability, self-management and interoperability. It totally relies on free/libre opensource software.
Systemli.org is a left network and technics-collective that was founded in 2003. Our aim is to provide safe and trustworthy communication services. The project addresses political activists and people who have a particular need to protect their data.
Fripost – the Free Email Association. Fripost organize the people who want an alternative to "free" e-mail services where you are constantly under surveillance and personal data is handed over to third parties.
Open Source WebMail Lite is a free community edition of full-featured WebMail Pro server application intended for users who need a clean and simple web mail application, which is fast and easy to use. Whether you need a free web browser based email client software for Windows ASP.
Switzerland
Germany
EU
Netherlands
United States
France
Protonmail is free, open-source, encrypted (more private). Lacks: calendar & good contacts feature, but these are in the pipeline. Protonmail cannot by design data-mine your software for it's own profit; Gmail makes it's money by violating your privacy that way.