Now this seems like a good idea – from Inc.com’s Secure Your E-mail, Mission Impossible Style:
BigString, which provides free, large-storage, Web-based e-mail accounts, allows users to send recallable, changeable, erasable, non-printable and self-destructing e-mails. E-mail senders can also track who reads an email and can control the number of times a message is read or forwarded. E-mail senders can set a time or date for e-mails to self-destruct and can create emails that can not be printed, saved, or forwarded by the recipient.
Clever. You knew it was just a matter of time before this level of security became real. Of course, it comes at a price. There are some emails that have to be forwarded. Imagine receiving some flame-mail that could not be shared with others.