Mail-0 (Zero) — Open Source Privacy-First Email App

Introduction

Mail-0 (also called Zero) is an open-source email application that puts privacy and security first. It provides a modern, clean email experience while ensuring users retain full ownership of their data, with optional AI features that respect privacy boundaries.

What Mail-0 Does

• Provides a full-featured email client with a polished, modern interface
• Connects to standard email providers via IMAP/SMTP protocols
• Offers AI-powered email categorization and smart replies with privacy controls
• Supports multiple email accounts in a unified inbox
• Delivers end-to-end encryption options for sensitive communications

Architecture Overview

Mail-0 is built with Next.js and TypeScript on the frontend, using a modular architecture that separates the email protocol layer from the UI. The backend handles IMAP/SMTP connections and optional AI processing, while the frontend renders a responsive single-page application. Data flows through a clean API layer, and the AI features operate with explicit user consent.

Self-Hosting & Configuration

• Clone the repository and configure environment variables in .env
• Set up your IMAP/SMTP credentials for each email account
• Optionally configure AI provider keys for smart features
• Deploy with Docker or run directly with Node.js
• Configure TLS certificates for production deployments

Key Features

• Privacy-first design with no tracking or data collection
• Modern, responsive UI built with React and Tailwind CSS
• AI-powered email organization that runs with user consent
• Open-source codebase with transparent security practices
• Multi-account support with unified inbox view

Comparison with Similar Tools

• Thunderbird — mature desktop client but heavier and less modern UI
• Roundcube — web-based but lacks AI features and modern design
• ProtonMail — privacy-focused but proprietary and subscription-based
• Tutanota — encrypted email but closed-source client
• K-9 Mail — Android-only, no web interface

FAQ

Q: Does Mail-0 store my emails on its servers? A: No. Mail-0 connects directly to your email provider via IMAP/SMTP. Your emails stay on your provider's servers.

Q: Are the AI features required? A: No. AI features are entirely optional and require explicit configuration. The app works fully without them.

Q: Can I use Mail-0 with Gmail, Outlook, or other providers? A: Yes. Any email provider that supports standard IMAP/SMTP protocols works with Mail-0.

Q: Is Mail-0 production-ready? A: Mail-0 is under active development. Check the repository's README for the latest stability status before deploying in production.

Sources

• https://github.com/Mail-0/Zero
• https://mail0.link