A split proxy is configured for managing asynchronous MAPI communications between a client and a server by establishing a queuing structure for MAPI messages that make up the communications. The MAPI messages are subsequently exchanged between the client and the server using the queuing structure. Multiple remote procedure calls (RPCs) underlying the MAPI messages may be grouped together in batches for exchange between proxies of the split proxy. Also, when the client logs off from the server, a MAPI keep-alive process allows updates received at the server to be pre-populated to the split proxy for transfer to the client when it reestablishes a connection.