Grant administrative privileges on the basis of administrative groups. Exchange servers join administrative groups during installation. Exchange servers cannot move between administrative groups. Create administrative groups before you install Exchange servers.
The Exchange Administration Delegation Wizard is used to grant administrative permissions to users/groups within an Exchange organization.
The three levels of permissions are Exchange Full Administrator (can perform all functions including permission delegation), Exchange Administrator (can perform all admin functions except permission delegation), and Exchange View Only Administrator (can view configuration information, cannot modify Exchange objects).