SMTP to REST API Translator

A Dockerized Python SMTP server that receives emails and forwards them to a RESTful API endpoint.

Features

• SMTP Server: Listens for incoming SMTP connections
• Email Parsing: Extracts email content, headers, and attachments
• Authentication Support: Captures SMTP AUTH credentials (username/password)
• REST API Forwarding: Sends all email data as JSON to a configured API endpoint
• Attachment Handling: Base64-encodes attachments for API transmission
• Client Metadata: Includes client IP and other connection details

Quick Start

Using Docker Compose (Recommended)

1. Start the service:

docker-compose up -d

2. Stop the service:

docker-compose down

Using Docker (Manual)

1. Build the Docker image:

docker build -t smtp2api .

2. Run the container:

docker run -p 8025:8025 -e API_URL=http://your-api-endpoint/api/email smtp2api

Local Development

1. Install dependencies:

pip install -r requirements.txt

2. Create a .env file (optional):

cp .env.example .env
# Edit .env with your configuration

3. Run the server:

python3 app/smtp_service.py

Testing

A test script is included to verify the server functionality:

python3 tests/test_send.py

You can also use the included mock API server for testing:

# In one terminal
python3 tests/mock_api.py

# In another terminal
python3 app/smtp_service.py

# In a third terminal
python3 tests/test_send.py

Security Notes

• The server is configured with auth_require_tls=False for development. In production, enable TLS.
• SMTP credentials are forwarded in plain text in the JSON payload. Ensure your API endpoint uses HTTPS.
• Consider implementing IP whitelisting or additional authentication for production use.

License

MIT