gh-christianlouis-inboxconverge/docs/MVP.md

MVP (Minimum Viable Product) Plan

Overview

The MVP provides core functionality to replace Gmail's POP3 import feature with a self-hosted Docker solution.

MVP Scope

✅ Completed Core Features

1. POP3 Email Fetching

   • Connect to POP3 mailboxes using SSL/TLS
   • Support for multiple POP3 accounts via environment variables
   • Automatic deletion after successful retrieval

2. Email Forwarding

   • Forward emails to Gmail via SMTP
   • Preserve original email metadata (sender, date, subject)
   • Use Gmail App Passwords for authentication

3. Scheduling & Automation

   • Periodic checking at configurable intervals (default: 5 minutes)
   • Automatic startup and continuous operation

4. Throttling & Rate Limiting

   • Configurable emails per minute limit (default: 10/min)
   • Prevent Gmail quota issues
   • Smart delay insertion between sends

5. Error Handling & Notifications

   • Comprehensive logging (INFO, WARNING, ERROR levels)
   • Error notifications via Postmarkapp SMTP
   • Graceful handling of connection failures

6. Docker Deployment

   • Dockerfile for containerization
   • docker-compose.yml for easy deployment
   • Non-root user for security
   • Automatic restart on failure

7. Configuration Management

   • Environment variable-based configuration
   • .env.example template
   • Support for unlimited POP3 accounts

8. Documentation

   • Comprehensive README with setup instructions
   • Configuration guide
   • Troubleshooting section
   • Security best practices

MVP Validation Criteria

• Successfully fetches emails from at least one POP3 account
• Forwards emails to Gmail without data loss
• Runs continuously in Docker container
• Handles errors without crashing
• Sends error notifications
• Respects rate limits
• Complete documentation for setup

What's NOT in MVP

• Web UI for configuration
• Database for tracking processed emails
• Advanced filtering rules
• Email archiving
• Multiple destination addresses
• OAuth2 authentication
• Webhook notifications
• Metrics dashboard
• Email deduplication
• Custom retry policies

Success Metrics

1. Reliability: 99%+ uptime for email forwarding
2. Performance: Process emails within 1 minute of receipt
3. Scalability: Support at least 10 POP3 accounts
4. Usability: Setup time under 10 minutes
5. Security: No credentials stored in code or logs

MVP Timeline

• Phase 1 - Core Functionality (Completed)

  • POP3 fetching
  • SMTP forwarding
  • Basic error handling

• Phase 2 - Production Ready (Completed)

  • Docker containerization
  • Error notifications
  • Throttling
  • Comprehensive logging

• Phase 3 - Documentation (Completed)

  • README
  • Configuration guide
  • MVP plan
  • Roadmap

Next Steps (Post-MVP)

See ROADMAP.md for planned enhancements and future features.

Known Limitations

1. Single Destination: Only one Gmail address supported
2. No Filtering: All emails are forwarded without rules
3. No UI: Command-line and file-based configuration only
4. Basic Throttling: Simple time-based rate limiting
5. No Retry Logic: Failed forwards are logged but not retried
6. No Deduplication: Same email could be forwarded twice if fetched multiple times
7. Text Only: HTML emails are converted to plain text

Risk Mitigation

Risk	Mitigation
Gmail rate limits	Configurable throttling, max emails per run
POP3 server downtime	Error notifications, automatic retry on next cycle
Password exposure	Environment variables, .gitignore for .env
Data loss	Delete only after successful forward
Container crashes	Docker restart policy
Configuration errors	Validation on startup

Testing Recommendations

1. Functional Testing

   • Send test email to POP3 account
   • Verify forwarding to Gmail
   • Check original metadata preservation

2. Error Testing

   • Test with invalid credentials
   • Test with unreachable POP3 server
   • Verify error notifications

3. Load Testing

   • Test with 50+ emails
   • Verify throttling works
   • Check memory usage

4. Security Testing

   • Verify SSL/TLS connections
   • Check for credential leaks in logs
   • Test with non-root user

User Acceptance Criteria

• User can configure multiple POP3 accounts via .env file
• User receives forwarded emails in Gmail within 5 minutes
• User receives email notification when errors occur
• User can view logs to troubleshoot issues
• User can start/stop service with docker-compose
• Documentation is clear enough for non-technical users