Email Testing Services for STING Development

Current Setup: Mailpit

  • Connection: smtps://test:test@mailpit:1025/?skip_ssl_verify=true
  • Limitations: Basic functionality, no SMS support.

Alternative Email Testing Services

  • Pros:
    • Easy Docker setup
    • Web UI for viewing emails
    • API for automated testing
    • Supports SMTP authentication
    • No external dependencies
  • Docker Setup:
    mailhog:
  image: mailhog/mailhog:latest
  container_name: sting-ce-mailhog
  ports:
    - 1025:1025  # SMTP server
    - 8025:8025  # Web UI
  networks:
    - sting_local
  • Kratos Config: smtp://mailhog:1025

2. Mailtrap (Cloud Service)

  • Pros:
    • Cloud-based, no local setup
    • Team collaboration features
    • Email templates preview
    • Spam score analysis
    • Free tier available (500 emails/month)
  • Cons:
    • Requires internet connection
    • API key needed
  • Kratos Config: smtps://[username]:[password]@smtp.mailtrap.io:2525

3. MailCatcher

  • Pros:
    • Ruby-based, lightweight
    • Simple web interface
    • Catches all emails sent to it
  • Docker Setup:
    mailcatcher:
  image: schickling/mailcatcher:latest
  container_name: sting-ce-mailcatcher
  ports:
    - 1025:1025  # SMTP
    - 1080:1080  # Web UI
  networks:
    - sting_local

4. Inbucket (Modern Alternative)

  • Pros:
    • Written in Go, very fast
    • REST API and Web UI
    • Supports email retention policies
    • POP3 support
  • Docker Setup:
    inbucket:
  image: inbucket/inbucket:latest
  container_name: sting-ce-inbucket
  ports:
    - 2500:2500  # SMTP
    - 9000:9000  # Web UI
    - 1100:1100  # POP3
  networks:
    - sting_local

5. smtp4dev (Windows-friendly)

  • Pros:
    • .NET Core based
    • Modern web UI
    • IMAP support
    • Email forwarding rules
  • Docker Setup:
    smtp4dev:
  image: rnwood/smtp4dev:latest
  container_name: sting-ce-smtp4dev
  ports:
    - 5000:80    # Web UI
    - 25:25      # SMTP
    - 143:143    # IMAP
  networks:
    - sting_local

SMS Testing Services

  • Pros:
    • Free test numbers
    • No charges for test messages
    • Realistic API experience
  • Setup:
    • Use test credentials from Twilio console
    • Test phone numbers that always succeed/fail
    • Magic numbers for testing different scenarios.

2. TextMagic Sandbox

  • Pros:
    • API sandbox environment
    • Free testing
    • Good documentation.

3. Mock SMS Service (Local)

  • Custom Implementation:
    # Simple Flask app to mock SMS sending
@app.route('/api/sms', methods=['POST'])
def send_sms():
    data = request.json
    # Log SMS to file/database
    # Return success response
    return jsonify({"status": "sent", "id": str(uuid4())})

For comprehensive testing with both email and SMS:

# docker-compose.override.yml
services:
  # Email testing
  mailhog:
    image: mailhog/mailhog:latest
    container_name: sting-ce-mailhog
    ports:
      - 1025:1025  # SMTP server
      - 8025:8025  # Web UI at http://localhost:8025
    networks:
      - sting_local
    restart: unless-stopped

  # SMS mock service
  sms-mock:
    image: sting/sms-mock:latest
    build:
      context: ./services/sms-mock
      dockerfile: Dockerfile
    container_name: sting-ce-sms-mock
    ports:
      - 8030:8030  # API and Web UI
    environment:
      - LOG_LEVEL=debug.
    volumes:
      - sms_logs:/app/logs
    networks:
      - sting_local
    restart: unless-stopped

  kratos:
    environment:
      # Override email config
      - COURIER_SMTP_CONNECTION_URI=smtp://mailhog:1025.
      # Custom SMS provider config
      - COURIER_SMS_PROVIDER=generic
      - COURIER_SMS_REQUEST_CONFIG_URL=http://sms-mock:8030/api/sms
      - COURIER_SMS_REQUEST_CONFIG_METHOD=POST
      - COURIER_SMS_REQUEST_CONFIG_BODY='{"to": "{{ .To }}", "message": "{{ .Body }}"}'.

Implementation Steps

  1. Replace Mailpit with MailHog:

    • Better UI
    • API for automated testing
    • More reliable.

  2. Add SMS Mock Service:

    • Create simple service to log SMS
    • Integrate with Kratos courier.

  3. Update Kratos Config:

    • Configure email templates
    • Set up SMS templates
    • Test both channels.

  4. Create Debug UI:

    • Add email viewer to debug page
    • Show SMS logs
    • Test sending capabilities

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