Use the Address Booktab to enable the expansion of Exchange distribution groups. By enabling distribution group expansion, you enable users to invite all or selected members of a distribution group to an instant messaging (IM) conversation without having to search for and add each one individually. The Address Booktab displays the internal and external URLs that identify the location of the Web service that will enable distribution group expansion for internal and external clients.

To configure address book query settings for a Web Components Server

  1. Open the Office Communications Server 2007 R2 snap-in.

  2. In the console tree, expand the forest node, and then do one of the following:

    • For an Enterprise pool, expand Enterprise pools, right-click the pool, click Properties, and then click Web Component Properties.

    • For a Standard Edition server, expand Standard Edition servers, right-click the pool, click Properties, and then click Web Component Properties.

  3. Click the Address Booktab, and then do one or more of the following:

    • To enable address book queries, click Enable Address Book Query.

    • To enable the expansion of distribution groups, click Enable Distribution Group Expansion.

    • In Maximum Group Size, select the maximum size of the distribution group. The default value is 100 and the maximum value is 1000.