Is it possible to e-mail word, excel or powerpoint files that self-destruct after a set expiry time. Our business uses NDA agreements to manage confidentiality but we feel uncomfortable e-mailing Office documents that contain valuable corporate information. It would be reassuring if we knew they would automatically delete themselves after 3 months.
It would be difficult to set them to delete themselves - the file might get picked up as a virus plus what if it is on read-only media such as a cd.
The best option would be to make the text unreadable after a certain time - you might be able to achieve it with drm but I haven't tried it: http://en.wikipedia.org/wiki/Digital_rights_management#DRM_and_documents