With DS Site Configuration, you can set values for various items in the directory for your site. The directory contains information about your site, just as a phone book contains information about a community. It contains objects such as mailboxes, distribution lists, public folders, custom recipients, and mailbox agents. This information is used by other components in Microsoft Exchange Server, such as server services.
Use information in the directory to set up offline Address Books and establish custom attributes. You can also determine how long to save a tombstone and how often to remove one. A tombstone is a marker indicating that you have deleted an object from your system.