In most organizations, an estimated 83 percent of all communications are electronic, with the vast majority of those communications going through an email system. In a 2004 survey of 840 US companies, 21 percent of respondents had their email and instant message data subpoenaed, up from 14 percent in 2003.

The cost of storage per megabyte has been on a continuous drop since the first electronic storage solution. At the same time the storage requirements have continued to grow at an almost inverse rate. Ten years ago, 100GB of disk space on your Exchange server would have seemed outrageous for most organizations. Today, that has become nearly a minimum for an Exchange server.

With the release of Exchange 2003 SP2, Microsoft has increased the maximum database size in the Standard Edition of Exchange from 16GB to 75GB. Microsoft has also increased the scalability of Exchange so that a single server, or cluster node, can host more than 4,000 mailboxes. In addition, the number of messages users send each day continues to grow—as does the size of attachments in messages. So while the overall cost per megabyte has continued to fall, the management cost of the servers that host the data has stayed about the same, or increased on a per server basis due to server consolidation and increased server complexity.