Initial commit: Postfix mail server with SES relay

- Containerized Postfix configuration for mailing list management
- Environment-based configuration for SES credentials
- Template-based config generation for flexibility
- Static virtual aliases (Phase 1)
- Prepared for future web interface and SQL backend (Phase 2+)

Features:
- Docker Compose orchestration
- Secure credential management via .env
- Configurable SMTP host/port
- Git-ignored sensitive files
- Comprehensive documentation

README.md

@@ -0,0 +1,124 @@
+# Mail List Manager
+
+A containerized mailing list management system built around Postfix as an SMTP relay through Amazon SES.
+
+## Architecture
+
+**Current (Phase 1):** Static configuration with environment-based credentials
+- Postfix container configured as SES relay
+- Static virtual aliases for mailing list distribution
+- Environment variable configuration for security
+
+**Planned (Phase 2+):** Web interface with SQL backend
+- Web frontend for list management (view/add/remove members)
+- SQL database for member storage
+- Dynamic Postfix configuration generation
+
+## Quick Start
+
+1. Copy the environment template:
+   ```bash
+   cp .env.example .env
+   ```
+
+2. Edit `.env` with your SES credentials and configuration:
+   ```bash
+   # Required: Your SES credentials
+   SES_USER=your_ses_access_key
+   SES_PASS=your_ses_secret_key
+   
+   # Optional: SMTP configuration (defaults to EU West 2)
+   SMTP_HOST=email-smtp.eu-west-2.amazonaws.com
+   SMTP_PORT=587
+   ```
+
+3. Build and start the mail server:
+   ```bash
+   docker-compose up --build
+   ```
+
+4. Test mail delivery:
+   ```bash
+   # From inside container
+   docker-compose exec postfix bash
+   echo "Test message" | mail -s "Subject" community@lists.sasalliance.org
+   
+   # Check logs
+   docker-compose logs -f postfix
+   ```
+
+## Configuration
+
+### Adding Mailing Lists (Current)
+
+Edit `postfix/virtual_aliases.cf`:
+```
+newlist@lists.sasalliance.org   recipient1@domain.com, recipient2@domain.com
+```
+
+Then rebuild the container:
+```bash
+docker-compose up --build
+```
+
+### Domain Configuration
+
+The system is configured for:
+- **Hostname**: `lists.sasalliance.org` (mailing lists)
+- **Origin Domain**: `sasalliance.org`
+- **SES Region**: EU West 2 (configurable via `SMTP_HOST`)
+
+## Security
+
+- SES credentials are stored in `.env` (git-ignored)
+- SASL password files have restricted permissions (600)
+- TLS encryption enforced for SES relay
+- Only localhost and configured hostname accepted for local delivery
+
+## Development
+
+### Project Structure
+```
+├── docker-compose.yaml          # Service orchestration
+├── .env                        # Environment configuration (not in git)
+├── postfix/
+│   ├── Dockerfile             # Postfix container build
+│   ├── entrypoint.sh          # Runtime configuration processing
+│   ├── main.cf.template       # Postfix main configuration template
+│   ├── sasl_passwd.template   # SES authentication template
+│   └── virtual_aliases.cf     # Static mailing list definitions
+└── .github/
+    └── copilot-instructions.md # AI agent guidance
+```
+
+### Environment Variables
+- `SES_USER`: AWS SES access key ID
+- `SES_PASS`: AWS SES secret access key  
+- `SMTP_HOST`: SMTP server hostname (default: email-smtp.eu-west-2.amazonaws.com)
+- `SMTP_PORT`: SMTP server port (default: 587)
+
+### Debugging
+
+Monitor mail delivery:
+```bash
+# View all logs
+docker-compose logs -f
+
+# Filter for delivery status
+docker-compose logs postfix | grep -E "(sent|bounced|deferred)"
+
+# Check Postfix queue
+docker-compose exec postfix postqueue -p
+```
+
+## Roadmap
+
+- [ ] Web frontend for mailing list management
+- [ ] SQL database backend for member storage
+- [ ] Dynamic configuration generation from database
+- [ ] Multi-service Docker Compose architecture
+- [ ] Migration tools for static → dynamic configuration
+
+## License
+
+MIT License - see LICENSE file for details.