Best Open Source Alternatives to Gmail

Compare the best free and open-source alternatives to Gmail — self-hosted and desktop replacements you fully control, ranked by GitHub stars, license and platform support.

Curated by open-source.store · Updated August 2026 · 1 alternatives

Gmail

Proprietary SaaS

PricingPaid

Platformsdesktop, web

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Gmail alternatives compared

Open-source alternatives to Gmail, compared by stars, license and platform
Tool		License	Platforms	Self-hosted
Tuta (Experimental)	19	—	Linux	No	Jul 2026	Visit

Top open-source Gmail alternatives

Tuta (Experimental)19

Secure email, calendar & contacts