previously, when deleting emails in the mail client, when using shift+del, a warning window appeared , something like " are you sure that emails will be permanently deleted without the possibility of recovery" and there was a checkbox, something like " do not ask again". this checkbox was never set, the warning always came out , but suddenly stopped coming out, letters are deleted without warning, I assume that the checkbox was accidentally set. how do I set up a warning about deleting emails again?