PSTs, why and how to get rid of them

cup_coffee-256I’ve never made a secret of my continuing loathing of PST files, I just never displayed it on my blog. I always felt it would be too negative, while I always try to to find the positive angle to a story. Today, finally, I have positive news on PSTs!

What’s wrong with PSTs then?

If you need to ask this question, I guess you’ve never been an admin for a (enterprise) networking infrastructure, never needed to migrate between messaging solutions or never had the generic trouble related to PSTs.

redshieldPSTs, or PST files, are files with the *.pst extension. Microsoft Outlook is the program a user would typically use to open these kinds of files. Microsoft calls them personal folder files or personal stores. And yet, many problems with PSTs are related to people treating them as anything but personal files…
The problem with PSTs, in short, is:

  1. PSTs cannot be used in multi-user and multiple-devices-per-user scenarios.
  2. PSTs cannot be accessed through Outlook Web Access or Outlook Web App.
  3. PSTs are storage inefficient. In a large messaging environment, archiving to PSTs would clog up file servers. Where older versions of Exchange Server use Single Instance Storage and newer versions of Exchange Server compress the database, PSTs don’t offer any of these optimizations. A 10MB message sent to a hundred recipients, stored by these hundred recipients in their respective PSTs would clog up the file server with 1GB. Not an uncommon scenario. Because of this, PSTs are mostly stored locally, exposed to the risk of data loss, data theft, etc.
  4. PSTs used to be limited to 2GB file sizes. If a PST grew larger than that, it would end up corrupted and needed to be fixed (with pst2gb.exe). To accommodate larger files, Microsoft introduced the Unicode format with Office 2003, but for a long time the new Unicode format wasn’t supported by the Exchange Migration Wizard (migwiz.exe) and PSTs in Office 2003 did not always migrate gracefully.
  5. PSTs are excluded from synchronization of offline files and excluded from use with programs like Windows Live Mesh.

In the old days, avoiding problems with PSTs would mean you would have large Exchange databases (with long backup windows, restore times, etc.), extensive Exchange Public Folder stores (without quotas) or an expensive mail archiving solution. Not quite desirable solutions either.


…and now, for someting positive

As I stated at the beginning of this blogpost, I would say something nice about PSTs.

The positive thing is Microsoft has executed on the extinction of PST files in small to medium-sized networking infrastructure environments, removing most of the barriers in place:

vaultExchange Archiving

No longer do you have to invest in an expensive mail archiving solution. Exchange Archiving is now built into Exchange Server and Exchange Online, with users being able to access their archives with Microsoft Outlook (as part of Office Professional Plus) and Outlook Web App (OWA).

The archiving database is separate from the Exchange private store and, thus, does not interfere with the backup and restore of this database. If you do want to get rid of archives, put them in Exchange Online.

WizardOrangePST Capture

Microsoft, earlier this week, has released a free tool to track down PSTs in networking environments. It’s called Exchange PST Capture and you can use it to discover and import PSTs into Exchange Server and Exchange Online. PST Capture helps. By optionally installing PST Capture Agents on target machines, you can determine where PSTs are located and who their owners are via the PST Capture Console.

Now, not only does Exchange Server and Exchange Online offer archiving, you can also track down any existing PSTs and put them into their owners’ respective archives automatically.


So, if you been waiting to get rid of those PSTs, then now is the time!


Microsoft Exchange PST Capture free

Further reading

Sean McNeill – Hands on with the PST Capture Tool
PST Capture
.PST Capture is now available as a free download
Outlook Blog – PST Capture: New tool to manage those ever multiplying inboxes
Microsoft Exchange PST Capture tool released!
Microsoft Exchange PST Capture Tool
Microsoft PST Capture Tool for Exchange 2010 and Office 365 released – Microsoft Exchange PST Capture tool released
.PST, Time to Walk the Plank

One Response to PSTs, why and how to get rid of them


    Especially in medium to large environments the MS PSTCapture Tool is covering just a part of the needed workflow. A lot of questions are still unanswered by MS.

    We have published an interessting Whitepaper related to PST Migrations to Exchange 2010.

    Happy reading 🙂


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