Introduction to Exchange Address Lists

Exchange address lists are dynamically created collections of visible recipient objects that are produced as a result of a Lightweight Directory Access Protocol (LDAP) query based on the specific attributes with which the recipient objects have been configured. Address lists can contain any of the available recipient object types users, groups, contacts, and public folders. Because these address lists are dynamically created by an LDAP query, administrators do not need to dedicate time to maintaining them every time recipient objects are added or removed. All Exchange address lists are created and stored in the child containers that are located within the Recipients container of the Exchange System Manager, as shown in Figure 5.1.

Figure 5.1. Exchange creates several default address lists during its installation.

Public folders are a very special type of Exchange recipient that we have not discussed up to this point. Public folders are covered in Chapter 6, "Managing, Monitoring, and Troubleshooting the Exchange Organization."

Four types of Exchange address lists exist as discussed in the following sections: global, default, offline, and custom.

The Global Address List

The global address list (GAL), much as its name implies, is the primary address list with which Exchange users will become familiar. The GAL contains all Exchange recipient objects in the entire organization and is retrieved from the global catalog servers. When Exchange is first installed, a default GAL is created and automatically contains all Exchange recipients as they are created.

The Default Address Lists

The default address lists provide the same information as the GAL does, but in a more distilled manner. Default address lists are created from a specific set of attributes of recipient objects. The default address lists are automatically created when Exchange is installed and require no additional administrative action. Exchange provides five default address lists: All Contacts, All Groups, All Users, Public Folders, and the Default Global Address List (GAL) discussed previously.

In most smaller organizations, the default address lists are sufficient. However, in cases in which users in your Exchange organization need to have custom address lists, such as those created by location or department, you need to create one or more custom address lists as discussed in the "Creating New Custom Address Lists" section later in this chapter.

The Offline Address List

The default offline address list is an address list that is available to Exchange users when they are working offline with an offline folder, an .OST file. By default, the default GAL is used to create the default offline address list. If desired, you can create additional offline address lists from any of your default, global, or custom address lists. Bear in mind that for the users on a mailbox store to be able to use an offline address list, it must be associated with their mailbox store.

Using an offline address list, users can search for recipients when working offline to facilitate the composition of email messages. When the user reconnects to the Exchange organization, the offline folder is synchronized back into the user's mailbox and any messages composed during this time are sent automatically.

Custom Address Lists

You can create any number of custom address lists that are required to meet the needs of your organization. Typically, you create custom address lists to make it easier for users to locate email addresses, for example, in a company that has many different divisions or departments and thousands of users. Another typical reason you might make custom address lists is if you have a need to create an address list that only certain users can see and use. Custom address lists can be nested as required and are created from LDAP queries that you define.