MAPI provides you with several ways to retrieve data because many properties can be duplicated on a message, on a folder, and on an information store. One strategy for improving efficiency is to find the data retrieval path that generates the smallest number of RPCs and MAPI calls. When several MAPI calls can be used to get the same data, test for the best performance by timing each, then using the most efficient call.
A Microsoft Exchange Client application opens a folder, gets the hierarchy table, sets the columns, sends the message, opens the message, and retrieves a property to determine which language the client is using.
This application can obtain the information more quickly by setting the columns on the MAPI display table, requesting rows, and setting a parameter to the desired property. This creates a large savings in CPU use, saves memory resources, and reduces the number of RPCs generated.