Global Settings, a feature in Microsoft Exchange 2000 Server, is ideal for organizations with uniform delivery or message formatting requirements. You need to create your settings once, at the organization level, and then turn off the corresponding settings at the mailbox or virtual server. Global settings will apply to all relevant objects in your organization, providing administrative convenience.
If there are exceptions in your organization, such as a group of users with different message formatting requirements than the rest of your organization, you can make the necessary configurations at the virtual server or individual mailbox level. These setting will always override global settings.
To learn more about global settings in Exchange: