Best Open Source Alternatives to Gmail

Zero is an open-source, self-hosted alternative to Gmail that combines PostgreSQL storage with automated AI triage and conversational inbox search.

vs Gmail: a free, open-source option you fully control, licensed MIT.

UnInbox is an open-source collaborative email platform that replaces Front with shared inboxes, internal thread notes, and task workflow statuses.

vs Gmail: a free, open-source option you fully control.

Twake Mail is an open-source mobile email client using JMAP to deliver private, protocol-driven messaging without proprietary tracking.

vs Gmail: a free, open-source option you fully control, licensed AGPL-3.0.

Tuta is a post-quantum encrypted alternative to Gmail and Outlook, providing zero-knowledge email, calendars, and custom domains for Linux teams.

vs Gmail: a free, open-source option you fully control.