Microsoft has announced it will release PST Capture, a free tool to search .PST files, import them into Exchange Server 2010 and Exchange Online and (optionally) destroy the files.
Exchange mailbox data is stored on Exchange servers – either on-premises in your organization’s datacenter, or in Exchange Online if you’re using Microsoft’s new Office 365 cloud service. Historically, Outlook users have used .PST files to store messages on their computers in order to reduce the size of their mailbox on Exchange or simply to keep an offline copy.
However, with ever-increasing mailbox sizes (see Exchange 2010 Large Mailbox Vision Whitepaper), lower storage costs and Personal Archives – the email archiving functionality in Exchange 2010 and Exchange Online, finding and eliminating .PST files is becoming an important concern for organizations. Besides preventing data loss, data leakage and theft, moving PST files scatterred all across an organization back into Exchange also allows you to respond quickly to eDiscovery requests and reduce discovery costs.
PSTs and OSTs
Personal Folders or .PST files are used by Microsoft Outlook to store messaging data locally on a user’s computers. Unlike Offline Folders (.OST files), which are used by Outlook to store a copy of the user’s Exchange mailbox when using Outlook in Cached Exchange Mode, .PST files aren’t synchronized to the user’s Exchange mailbox. Users must either manually move or copy mesages or folders from their Exchange mailbox to a PST file, or use Inbox rules to automatically move or copy messages to a folder in the PST file.
.OST files are tied to the user’s Outlook configuration (aka Outlook profile) on the computer where they’re created, whereas .PST files allow for easier portability of data – users can access .PST file data on any computer which has Outlook installed.
For more details about .PST and .OST files, see Introduction to Outlook Data Files.
Importing and exporting .PST files over the years
In the past, Microsoft has provided other tools to import .PST files to Exchange and to export Exchange mailbox data to a .PST file.
- Before Exchange 2007, Exchange administrators used Microsoft Exchange Server Mailbox Merge Wizard (ExMerge) to export/import Exchange mailboxes to/from .PST files.
- In Exchange 2007, Microsoft introduced the Import-Mailbox and Export-Mailbox cmdlets, allowing administrators to perform these tasks from the Shell. See How to Import Mailbox Data and How to Export Mailbox Data in Exchange 2007 documentation.
- In Exchange 2010, mailbox import and export is handled by the new Microsoft Exchange Mailbox Replication Service which performs asynchronous import and export of mailboxes to/from PST files. The Import-Mailbox and Export-Mailbox cmdlets are replaced with the New-MailboxImportRequest and New-MailboxExportRequest cmdlets, which offer more flexiblity and don’t require Outlook to be installed on the computer from which these cmdlets are run. For details, see Understanding Mailbox Import and Export Requests.
None of these tools have allowed you to search and import .PST files stored on users’ computers or to import messages from a .PST file to a cloud-based mailbox (a mailbox hosted in Exchange Online, a part of Microsoft’s new Office 365 service).
Over the years, a number of third-party tools have also thrived to help Exchange admins to easily import .PST files. Last year, Microsoft also released documentation detailing the PST file format, and two open source tools on CodePlex – the PST Data Structure View Tool (PSTViewTool) and PST File Format SDK. More in Microsoft goes open source with Outlook PST format.