A method for exchanging message data in a distributed computer system between a sending and a receiving hardware system. The sending hardware system includes a first memory system and a receiving hardware system which includes a second memory system with a second data buffer and a second memory region. The sending hardware system and the receiving hardware system are coupled via a non-transparent bridge unit. The method includes allocating empty memory, writing information about the empty memory, copying payload data directly from the sending hardware system to the empty memory locations, and writing information about the copied payload data to the second data buffer of the second memory system inside the receiving hardware system. A computer program product for carrying out the method is also provided.