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

.gitignore

@@ -0,0 +1,15 @@
+# Environment variables with sensitive credentials
+.env
+
+# Docker build artifacts
+.dockerignore
+
+# IDE files
+.vscode/
+.idea/
+*.swp
+*.swo
+
+# OS files
+.DS_Store
+Thumbs.db