The MAPI_PropertyListSetValue() function sets the value of a property in the specified property list.
MAPI_PropertyListSetValue(property_list_ID, property_ID, property_value)
• property_list_ID – A long integer specifying the property list in which a value is being set.
• property_ID – A long integer specifying the ID of the property being set.
• property_value – A variable containing the property value. The variable type will depend on the property being set.
A boolean. True indicates the property value was successfully set, while false indicates it was not.
The MAPI properties are available in the library on MSDN (msdn.microsoft.com). They are also found in the MAPITags.h source file of the Windows SDK. The MAPI property values are found in the MAPIDefS.h source file of the Windows SDK.