Source: Any Destination: Exchange/Microsoft 365
Error encountered during a migration to Exchange/Microsoft 365.
Service Exception processing request. Code: ErrorFolderExists, Message: A folder with the specified name already exists., Retry
The reason for this error, is that the source platform has a native folder - 'Notes' for example, and the destination Exchange/Outlook also has a native Notes folder, but only for Outlook Notes.
The source folder needs to be renamed for a migration to work.