version: '2' volumes: queue: services: postfix: build: . image: fphammerle/postfix ports: ['127.0.0.1:25:25'] volumes: - queue:/var/spool/postfix:rw environment: POSTMAP_PATHS: | /etc/postfix/edit-docker-compose.yml /etc/postfix/replace-me security_opt: [no-new-privileges] restart: unless-stopped # https://docs.docker.com/compose/compose-file/compose-file-v2/