Deleting from Sent view

If a user has moves a message from the Sent view to a folder and then deletes the message, it is gone from both locations, right?

If the user sets the “Remove only” option and deletes from the Sent view, it is only removed from the view and not the folder, right?

I have found that, once the “Remove only” option is set, it only affects newer memo’s. Older messages are deleted from folders if they are deleted from the Sent view. Does anyone know a fix or suggestion?