Outlook Express makes it easy to track down an e-mail address or telephone number. To find that certain someone ù whose name you already know ù select EditûFind People. In the resulting window, you can enter a name, an e-mail address, or both, and select from any of seven online people-searching services. Unfortunately, you can't search them all simultaneously.

Caption: Search for e-mail addresses with Outlook Express

Don't expect absolute success, either. Only two of the seven services gave my primary e-mail address, and many of them cited addresses that I no longer use.