Most business professionals today spend between 20% and 50% of their working time using e-mail: reading, ordering, sorting, ‘re-contextualizing’ fragmented information and of course writing emails. Use of e-mail is increasing due to trends of globalization such as distribution of organizational divisions and outsourcing.
When a user receives an email message and hits a reply button to type a response, an initial message is copied to a mail window buffer, and the user can edit the initial message. For example, the user may delete everything but a single paragraph to which the user wants to respond. The user may then send the response to the sender of the initial message, as well as some other users who were not the recipients of the initial message. Currently, the users who join the email thread late have no way of knowing how the initial message looked like in its original form. In particular, if the initial message was partially erased, they cannot view the erased portions, and even if the initial message looks complete, they cannot be certain that it has not been modified by other recipients.