Configuring the Global Address List
The Global Address List (GAL), also known as corporate address book or company directory, is a listing of all employees within an organization or department. GAL is a commonly used feature in mail systems so users can look up another user's information by first or last name, without having to know the complete email address.
GAL is configured on a per-domain basis. The GAL mode setting for each domain determines where the GAL lookup is performed. The GAL Configuration Wizard is used to configure the attributes. Select one of the following GAL configurations:
Internal. The Zimbra LDAP server is used for directory lookups.
External. External directory servers are used for GAL lookups. You can configure multiple external LDAP hosts for GAL. All other directory services use the Zimbra LDAP service (configuration, mail routing, etc.). When you configure the external GAL mode, you can configure GAL search and GAL sync separately. Configuring search and sync separately lets you configure different search settings and sync settings.
Both. Internal and external directory servers are used for GAL lookups.