To assign an administrative role to a user or to a group, open up the Exchange Management Console and navigator to the Organization Configuration work center. Next, click on “Add Exchange Administrator…” to start the Add Exchange Administrator wizard, which can be used to add a new Exchange administrator or enter a group that would be responsible for administrating the Exchange organization.
From within the wizard, click on the “Browse” button to locate the desired user from Active Directory. In this case, the user will be: “John Exchange.” The next stop will be to select the role and scope of John Exchange by clicking on the “Add…” button. This allows for the exact server or servers that are to be administered to be specified. Click on “Add” when done to execute the command.
Do note that John Exchange will need to be manual added to the built-in local administrators group on the server in order to fully administer the Exchange Server. This warning appears as the final step of the wizard, and can be dismissed by clicking on “Finish.” Administrators should of course ensure that this is done as the next step.