Outlook 2003 and 2007 both allow you to set up an e-mail form that will prevent recipients from forwarding your e-mails to anyone else as long as the sender and recipient both use Outlook. Although there are ways of getting around this-the recipient could cut and paste the content of your e-mail into another e-mail and then forward that-this isn't as easy as simply hitting "Forward." Plus, the cut-and-pasted e-mail would not have your "header" information on it, such as your name, your e-mail address, the time and date you sent the original message, etc.

The two links below contain detailed instructions to set this up. Even easier, click on the "Show Me" link and you will see a step-by-step video, with audio, that walks you through this. Note that the instructions show you how to prevent "Forwarding" and also prevent "Reply to All." You can set up a form that does both, or simply create one to prevent "Forwarding." The instructions are very straight-forward.