Mail Sink

A simple SMTP server for testing email flows locally. It provides a REST API to access received emails and includes a web UI.

Features

• SMTP server that captures all incoming emails
• Parses email content including HTML, plain text, and attachments
• REST API to retrieve emails and clear the mailbox
• Web UI for viewing and managing emails
• Single binary deployment with embedded UI

Usage

Building

You can use the provided Makefile to build both the UI and the Go binary in one step:

# Build everything
make

# Or separately
cd ui
npm install
npm run build
cd ..
go build -o mail-sink

Running

Using the Makefile:

# Run with default settings
make run

# Run with custom ports
make run-custom SMTP_PORT=2525 HTTP_PORT=3000

Or directly:

# Run with default settings
./mail-sink

# Run with custom ports
./mail-sink --smtp-port 2525 --http-port 3000

Development

To run the UI in development mode with hot reloading:

# Start the Go server
./mail-sink

# In another terminal, start the UI development server
cd ui
npm run dev

This will start the UI development server that proxies API requests to the Go backend.

Command line options

• --smtp-port PORT: SMTP server port (default: 1025)
• --http-port PORT: HTTP server port (default: 8080)
• --help: Show help

API

The following API endpoints are available:

• GET /api/emails: Get all received emails
• GET /api/emails/:id: Get a specific email by ID
• DELETE /api/emails: Clear all emails
• GET /api/info: Get server information (ports)

SMTP Configuration

To send emails to the Mail Sink, configure your email client or application with:

• SMTP Server: localhost
• SMTP Port: 1025 (or custom port)
• Authentication: None required (all authentication attempts are accepted)

License

MIT