[Unit] Description=Smail 邮件服务 After=network-online.target Wants=network-online.target [Service] Type=simple User=smail Group=smail # 运行环境仅由 root 可读写的独立文件提供,避免在 unit 中混入部署环境配置。 EnvironmentFile=/etc/smail/smail.env WorkingDirectory=/opt/smail ExecStart=/opt/smail/smail Restart=on-failure RestartSec=5s RuntimeDirectory=smail RuntimeDirectoryMode=0750 # 目录由 smail 进程拥有,允许主服务创建受保护的本机控制套接字。 NoNewPrivileges=true AmbientCapabilities=CAP_NET_BIND_SERVICE CapabilityBoundingSet=CAP_NET_BIND_SERVICE PrivateTmp=true ProtectHome=true ProtectSystem=full ReadWritePaths=/opt/smail/config /opt/smail/data /opt/smail/ssl /opt/smail/log -/opt/smail/plugins /run/smail [Install] WantedBy=multi-user.target