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

docker-compose.yaml

@@ -0,0 +1,8 @@
+version: "3.9"
+services:
+  postfix:
+    build: ./postfix
+    container_name: postfix
+    env_file: .env
+    ports:
+      - "25:25"