IT departments customarily impose limits on the size of Exchange mailboxes and provide users with the option to archive old e-mail in Outlook Personal Storage files (PSTs), which store e-mail on users’ local hard drives. As most IT professionals are aware, PST files are almost impossible to control centrally, frequently become corrupted and often grow enormous, creating management, backup and compliance headaches.
For organizations that can’t afford a third-party archiving system, such as Symantec ’s Enterprise Vault, Microsoft Exchange Server 2010 (Enterprise Client Access License)  can fill the bill. This basic solution stores data on the server, offering a manageable and searchable archive via the Outlook 2010 and Outlook Web Access interfaces, which users can access when online.
Follow these steps to configure a Personal Archive for a new Exchange 2010 user:
If you log in to Outlook 2010 with the new user’s account, you’ll see that after Outlook has completed the setup, the user has a mailbox and archive displayed in Outlook’s navigation pane (Figure 2).
Archive mailboxes are created in the same database as the user’s primary mailbox, and if a user’s mailbox is moved from one database to another, the archive mailbox is automatically moved at the same time. In Outlook 2010, archive mailboxes cannot be accessed when a user is offline because there is no synchronization to an offline storage file, as is the case with the user’s primary mailbox.
The Exchange Management Shell can also be used to create Personal Archives. Here’s how to run a command on the Exchange Server to create a Personal Archive for an existing user:
enable-mailbox “alias” -archive
You can also enable archive mailboxes for all recipients in a database, either from the management console, by choosing multiple recipients and right clicking to select Enable Archive under Microsoft Exchange On-Premises | Recipient Configuration | Mailbox, or from the shell using the following command, replacing “db” with the name of your database:
get-mailbox -database “db” | enable-mailbox -archive
In the Release to Manufacturing (RTM) version of Exchange 2010, users can manually copy folders or individual items from local PST files to their Personal Archive. Exchange 2010 Service Pack 1, which is due in the final quarter of 2010, will provide additional functionality for importing PST files to Personal Archives using the new-mailboximportrequest commandlet in the Exchange Management Shell.
Once you’ve migrated users’ local data to Personal Archives, you’ll want to prevent the creation of new PST files. Microsoft provides a set of Group Policy administrative templates that include settings allowing sysadmins to block users’ access to Outlook PST files. The Group Policy templates for Office 2010  can be downloaded from Microsoft’s website.
Once you’ve downloaded and extracted the templates, copy the contents of the ADMX folder to your central ADMX store (\\ad.contoso.com\SYSVOL\ad.contoso.com\Policies\PolicyDefinitions), excluding any language folders that are not required and replacing “ad.contoso.com” with your domain’s fully qualified domain name. If the PolicyDefinitions folder doesn’t exist, you can create it manually. Now create a Group Policy Object using the Group Policy Management Console on a domain controller to set one or both of the following settings for Outlook under User Configuration | Policies |Administrative Templates | Microsoft Office Outlook 2010 | Miscellaneous | PST Settings (Figure 3):
Once the settings have been configured, link the Group Policy Object to an Organizational Unit in Active Directory that contains users who have Outlook installed.
A retention policy (otherwise known as the default archive policy) is applied to Personal Archives by default and moves items from a user’s mailbox to their Personal Archive after two years, assuming that no other retention tag is set on an item. Additionally, users can tag folders or items to be automatically moved to the Personal Archive after a year, five years or never.
Exchange 2010 Service Pack 1 will bring some important changes to Personal Archives — most significantly, the ability to assign archive mailboxes to a different mailbox database than that in which the user’s primary mailbox resides. This will offer sysadmins the flexibility to place Personal Archives on less expensive storage devices and manage archive backups separately. There’s also an option to place archives on remote Exchange servers hosted by Microsoft’s Business Productivity Online Standard Suite service.
Another consideration is the availability of an upgrade to Outlook 2007 that will provide compatibility with Personal Archives. Finally, if you decide to apply your own retention policies to Personal Archives, this task will be much easier in SP1, which has a new user interface in the Exchange Management Console for implementing policies using a wizard. Configuration of retention policies in Exchange 2010 RTM can only be achieved using the command line.