According to one aspect of the present invention, there is provided a method of sending, from a processing system, a message to a destination identified in the message, the destination being one of a plurality of destinations, the message being sent via an intermediate module, each of the processing system and the destinations being connected to the intermediate module by individual point-to-point connections, comprising: resolving the address of the destination identified in the message; sending the message and the resolved address across the connection to the intermediate module; and at the intermediate module, receiving the message and resolved address, selecting, based on the resolved address, through which of the point-to-point connections the message should be sent; and sending the message through the selected connection.