A method and apparatus for ensuring that important confidential or proprietary information is not inadvertently released through email and similar transmissions. When file security firewall resident on a file security server or another network node receives an email intended for transmission, it determines whether the file revision history should be removed from any attachments. If so, the email is buffered and the attachments are extracted for file revision history by a file revision history remover associated with the firewall or an available proprietary file revision history remover. Once the file revision history removal is attempted, successfully or unsuccessfully, a reformed email is created, including either the original attachments or, in their place, a version of the attachment from which file revision history has been removed.