If Recover Deleted Items is set to Enabled, users can view items that have been deleted from Deleted Items and choose whether ...

If Recover Deleted Items is set to Enabled, users can view items that have been deleted from Deleted Items and choose whether to recover them to the Deleted Items folder or to delete them permanently using Outlook Web App. If Recover Deleted Items is set to Disabled, the items deleted from Deleted Items are retained, but users can't view, recover, or permanently delete them using Outlook Web App.