SMTP Relay with Web Dashboard
SimpleRelay offers a self-hosted, multi-tenant SMTP relay with a web dashboard, streamlining outbound email routing through various upstream providers. Built with FastAPI, Postfix, and Docker, it features DNS validation, per-sender access control, and robust management capabilities. This project appeals to the Hacker News audience by providing a powerful, centralized solution for complex email sending needs, especially for homelabs and developers.
The Lowdown
SimpleRelay presents a comprehensive self-hosted solution for managing outbound email, featuring a web dashboard to simplify the complexities of SMTP relaying. It aims to provide a secure and centralized system for routing emails through various upstream providers, making it ideal for environments where multiple applications or devices need to send email.
- Core Functionality: Routes outbound email through multiple upstream SMTP providers based on sender address, with multi-tenant support.
- Technology Stack: Built using FastAPI, Postfix, PostgreSQL, and Docker for easy deployment and scalability.
- User Panel Features: Offers a dashboard with statistics, a guided setup wizard for providers (with auto-detection and DNS validation), detailed mail logs, and per-provider access control. App password guidance is included for services like Gmail.
- Admin Panel Capabilities: Provides user management (activation, roles, relay limits, expiry), proxy management (outbound IPs, SOCKS5/HTTP proxies with testing and load tracking), and global sending limits per provider type.
- System Security & Features: Implements a Postfix-based relay with a built-in policy server ensuring no open relay is possible through mandatory IP whitelisting. It supports user registration with email verification, JWT authentication, relay expiry, health monitoring, and a multilingual UI.
- Homelab Use Case: Particularly highlights its utility for home networks, allowing all local devices to send emails through a single, managed relay, consolidating credentials and removing the need for public IPs or port forwarding.
In essence, SimpleRelay provides a robust, secure, and user-friendly platform for managing all outbound email traffic from a self-hosted environment, abstracting away much of the underlying complexity and offering significant administrative control.