Under certain boundary conditions, the Exchange Server information store can return an RPC response to the client's RPC request, which informs the client that the buffer the client had originally set up for the request is of insufficient size. The server's RPC response indicates this with the "ropBufferTooSmall" string; it also indicates how large the buffer needs to be. This, in itself, is not a issue for the client, as the client typically sets up an appropriately sized buffer for the response and makes the request again. This typically succeeds.
The issue occurs when the information store fails to properly account for all buffers overhead when it calculates the actual buffer size that is required. Thus, the information store indicates in the response that the buffer required is larger that the maximum RPC buffer size allowed. When this is the case, MAPI or CDO applications can report "insufficient memory" type of errors. http://support.micro...kb;en-us;241278