Hi @Holger Huo ,
Thanks for posting in our Q&A forum.
From your description I understand that you are having trouble renaming or deleting some of your folders in EWS. If there are any misunderstanding, feel free to let us know.
There are a few ways to rename a folder in EWS. One way is to use the Ews.RenameFolder method.
Another way is to use the UpdateFolder operation. You can use this operation to rename a folder by using the FolderType object and setting the DisplayName property to the new name.
In this case, you can try creating new folders with the correct names and relating them to their uses. To create a single folder, you can send a CreateFolder operation request message. The CreateFolder operation request indicates that the parent folder is the Inbox, the DisplayName is “Custom Folder”, and the FolderClass element value is IPF.Note.
Please refer to this blog: https://www.rebex.net/secure-mail.net/features/ews-folders.aspx#rename
Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.
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