As of March 26, 2019 Barracuda Networks will officially discontinue the first-generation ATP cloud services.
The second-generation ATP cloud service provides faster and multi-layered detection which leverages a global threat intelligence network that ingests vast amounts of diverse threat information from millions of collection points around the world. Additional information can be found here.
Please make sure to update to firmware version 7.2 which will automatically use the second-generation ATP cloud service. The release notes can be found here.