A web service includes a web service manager for servicing an originating message received from an originating client application, wherein the originating message has verification information a data package having an encrypted portion. The web service manager verifies that the originating message originated from an authorized originating client application, using the verification information. An identifier generator creates a data package identifier associated with the data package and a location within a data package store used for storing the data package. A message generator generates a notification message which is sent to a receiving computing system. Upon receipt of at least a portion of the notification message from the receiving computing system, the web service manager retrieves the data package from the data package store and initiates transfer the data package to the receiving computing system.