Query-Based Distribution Groups

A query-based distribution group is a new type of distribution group introduced in Exchange Server 2003. A query-based distribution group provides the same functionality as a standard distribution group. However, instead of specifying static user memberships, a query-based distribution group allows you to use a Lightweight Directory Access Protocol (LDAP) query to dynamically build membership in the distribution group (for example, "All full-time employees in my company").

Using query-based distribution groups results in a much lower administrative cost, given the dynamic nature of the distribution group. However, query-based distribution groups require higher performance cost for queries that produce a large number of results. This cost is equated with server resources (such as high CPU and increased working set) because every time an e-mail message is sent to a query-based distribution group, an LDAP query is executed against Active Directory to determine its membership.

Query-based distribution groups function in a pure Exchange Server 2003 deployment or in a native Exchange 2000 Server and Exchange Server 2003 deployment in which all servers running Exchange 2000 Server are running Service Pack 3 (SP3) with Windows Server 2003 global catalog servers.

For more information about query-based distribution groups, see Administration Features in Exchange Server 2003.

For more information about Exchange related attributes of query-based distribution group objects, see Exchange-Related Attributes of Query-Based Distribution Group Objects.

For information about troubleshooting query-based distribution groups, see Microsoft Knowledge Base article, "How to Troubleshoot Query-Based Distribution Groups."