Iterating through (edit)

• Loop through all folders
• Loop through all items
• Iterating through all folders
• Iterating through all items
• Iterate through a directory

+ EWS
+ EWS Managed API

+ MAPI
+ MAPIFolder
+ Microsoft.Office.Interop.Outlook.MAPIFolder
+ Outlook.Application
+ Outlook.Folders

How to iterate through a directory tree (C# Programming Guide)

https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/file-system/how-to-iterate-through-a-directory-tree