Smart Grids constitute massively distributed systems with many interconnected entities that require flexible and reliable machine-to-machine communication among each other. Providing such flexible and reliable communication enables the complex algorithms and control mechanisms that are necessary to ensure reliable grid operation and to trade energy generation and energy consumption to the mutual benefit of all involved entities. Messaging protocols such as the Extensible Messaging and Presence Protocol (XMPP) provide all the necessary mechanisms for implementing these tasks. Thus, they lend themselves to transmitting messages and data in Smart Grids by mapping Smart Grid protocols and data formats such as IEC 61850 and Common Information Model (CIM) to suitable messaging protocols. In this paper, we present an approach for mapping IEC 61850 and CIM to XMPP and elaborate on our experiences from implementing and evaluating this approach in a field trial conducted within the research project In2VPP.