A data security system, including a security manager computer making network API calls to a service that performs data-exchange transactions for end users, the API calls remotely controlling the service so that the security manager computer accesses an outgoing transaction that has already entered the cloud-based service, by generating one or more security platform rules that are applied by the service and cause the service to automatically transmit the outgoing transaction to an inspection location prior to transmission of the outgoing transaction to a destination, and a data inspector operative to inspect data of the outgoing transaction in the inspection location for data leakage, wherein the security manager computer further controls the service so as to transmit the outgoing transaction to the destinations when the data inspector clears the data, and to perform a remedial action regarding the outgoing transaction when the data inspector does not clear the data.