Summary MailFlow is a self-hosted, unified webmail client consolidating multiple IMAP/SMTP accounts into one interface. It targets individuals and businesses seeking enhanced email management, productivity, and data control via a privacy-focused, self-hosted approach.

How It Works MailFlow connects to email accounts via IMAP/SMTP, presenting a unified inbox. It uses heuristics and optional AI for automatic email categorization and offers one-click unsubscribe. Key features include real-time notifications, PWA installability, and robust backend services (Node.js, PostgreSQL, Redis) managed via Docker or native installs. Its design prioritizes user experience with conversation threading, rich text composition, and extensive customization.

Quick Start & Requirements The recommended installation uses pre-built Docker images, requiring Docker and Docker Compose. Configuration involves setting APP_URL, SESSION_SECRET, DB_PASSWORD, and ENCRYPTION_KEY in a .env file, followed by docker compose up -d. Optional Let's Encrypt setup is supported. A native install requires Node.js 20+, PostgreSQL 16+, Redis 7+, and Nginx.

Highlighted Details

• AI assistant for thread summarization and drafting (OpenAI-compatible).
• Progressive Web App (PWA) for desktop/mobile installation.
• SSO via OpenID Connect (OIDC) and OAuth2 for Microsoft 365.
• CardDAV support for contact synchronization.
• Optional GTD workflow with keyboard shortcuts.
• Two-factor authentication (TOTP, email fallback) and user management.
• Extensive customization: layouts, themes, keyboard shortcuts.

Maintenance & Community The README mentions "Contributing" and "Roadmap" sections but provides no direct links or details on specific contributors, community channels, or sponsorships.

Licensing & Compatibility MailFlow is dual-licensed: AGPL-3.0 for personal, self-hosted, and open-source use (requiring modifications to be shared under AGPL-3.0). A commercial license ($500/installation) is available for businesses unable to comply with AGPL obligations. The AGPL-3.0 license imposes strong copyleft restrictions.

Limitations & Caveats The AGPL-3.0 license's copyleft nature requires sharing source code modifications for distributed/hosted versions, potentially impacting commercial adoption. Integrations like Microsoft 365 require Azure App Registration. Older installations with disabled TLS verification may need admin configuration post-upgrade. A mandatory ENCRYPTION_KEY is required for versions 2.0.0+.