The Global Contacts functionality is a way to include external people within exchange, in the address book – and as a way to have an internal email address that goes to an outside person. NOTE: It doesn’t require another mailbox.
Ex: If there is a contractor working at your company, and you want to give them an "internal" email address, you can do so by creating a Contact. Any information that you want to include for the company address book can be included in their contact record, and be available through outlook.
Accessing Contacts
Log in to SiteControl, click the Email link, then click MS Exchange, and the Global Contacts link.
The Summary screen displays, which allows you to create, edit and delete contacts. If it is the first time you are using Hosted Exchange, or if you have deleted all of your Contacts, you will see the "empty" Summary screen.
The Summary screen will display any contacts after they are created. and allows you to Edit them.