GroupDocs.Viewer Cloud renders messages from all folders (including nested folders) by default. When you need to render items from a specific folder, set Folder property of the OutlookOptions class as shown in the example below. Please note that you should use the following convention for naming folders and subfolders to specify it in FolderName option: {Parent folder name}~~{Sub folder name}. Thus, if you need to render items from Inbox folder just specify Folder = “Inbox”; when you need to render subfolder named “Orion” that resides in a folder named “Urgent” that in turn resides in Inbox, set: Folder = “Inbox~~\Urgent~~\Orion”....msg" , "path" : "viewer/sample_o..."viewer/sample_ost/attachments/(Inbox)0.msg" , "downloadUrl" : "https://api.groupdocs...