A. Most groups in Active Directory (AD) contain static members--that is, group membership doesn't change unless you open the group and add users or other groups to it. In some cases, you might want to include in a group users who meet certain criteria and have AD reevaluate the group's membership each time the group is used. To evaluate a group's membership and determine who should be in the group, you use a Lightweight Directory Access Protocol (LDAP) query to create a query-based DG, a feature that Microsoft introduced in Exchange Server 2003.
The group-membership evaluation process uses more processor resources than using static groups because you must rerun the LDAP query that defines a group's membership every time you use the query-based DG.
To create a query-based DG, perform the following steps:
- Start the Microsoft Management Console (MMC) Active Directory Users and Computers snap-in (Start, Programs, Administrative Tools, Active Directory Users and Computers).
- Right-click the container in which you want to create the new query-based DG and select New, Query-based Distribution Group.
- Enter a name for the DG and click Next.
- You can select the root container that the query will search for matching objects. By default, this is the container in which you're creating the new object; however, you can change the default root container by clicking the Change button.
- You can define a standard type of query-based group that filters members according to the criteria that the figure at Figure shows. Alternatively, you can select "Customize filter" and click Customize to set up a customized filter that contains your own criteria. After you click Customize, you'll see the Find Exchange Recipients dialog box. Select the Advanced tab to define the attributes of the objects and the values that AD will use to evaluate the membership.
- After you've finished configuring the query-based DG, click Next.
- Click Finish.
You can view a query-based DG's current membership by right-clicking the DG and selecting Properties, then selecting the Preview tab. Remember that query-based DGs are evaluated against a Global Catalog (GC); if a GC isn't available, Exchange places the evaluation in a retry state and reattempts it in 1 hour.