oldium/microsoft-smtp-oauth2-proxy repository overview

⁠Microsoft SMTP OAuth2 Proxy for Next.js

This is a Next.js⁠ project providing a proxy server to allow connecting to Microsoft OAuth2-authenticated SMTP servers using basic authentication.

The home page of the project is here⁠.

Features:

• 🛡️ OAuth 2.0 authentication with Microsoft via web UI.
• 🧑‍💼 User login access rules.
• 🕸️ Single Node.js listening web server exposing just one port for web UI and API.
• 🐋 Docker-ready.
• ✉️ Sending emails using the SMTP protocol.
• 📬 Optional unprotected port for local trusted clients.
• 💡 Mixed-mode operation with independent SSL/TLS and STARTTLS connections for client and downstream server.
• 🎉 Allows to use single port for SSL/TLS (a.k.a. implicit TLS) and STARTTLS connections (see SMTP_AUTOTLS_PORT variable in [.env.example][env-example]).
• 🔁 Automatic retry on transient network errors when refreshing OAuth2 authentication tokens from Microsoft.
• 🛡️ Safer proxy handling by ignoring untrusted X-Forwarded-* headers.
• 🧹 Graceful shutdown that terminates idle connections.