Microsoft to release PST Capture tool to search, import and destroy PST files

by Bharat Suneja

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.

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.

{ 4 comments… read them below or add one }

Shawn Z August 2, 2011 at 9:23 am

1) Download “ExMerge” on to a Windows 2003 server with Exchange running on it.
2) Copy “exchmem.dll” to the folder with the “ExMerge” contents.
3) Give full perms to administrator or the user you logged in as to the server and mailboxes.
a. In Exchange Manager, right click in server, properties and then security
b. Uncheck inherit
c. Add everyone, and give full control to everyone.
d. Take ownership
This ensures that you have the require “send as” and “receive as”, but the step here are very insecure. While this is insecure, it does effectively allow a mailbox backup or each user for a system that is about to be decommissioned.


Steve M August 31, 2011 at 9:46 am

ExMerge 2003 suffers from the same 2GB limitation of older Outlook versions. If the mailbox is over 2GB, the contents will be truncated.

Better to open the mailbox with Outlook 2010 and export contents to a PST.


Manish Gupta March 31, 2018 at 2:14 am

Try SysTools Office365 Backup and Restore software to import PST file to Office 365 Also one can backup Office 365 mailbox to PST using this solution.


Manoj July 12, 2018 at 2:10 am

Thanks for briefing about PST Capture tool. It’s a great tool for importing PST files to Exchange Server 2010. But when we talk about PST to Office 365 migration that time using Azure AzCopy & PowerShell become quite complex task. In other hand MailsDaddy is providing GUI based tool to import PST files to Exchange Online.


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