Outlook is the industry standard groupware tool. Organizations depend on it for email, calendaring, tasks, contacts… it is often the heart and soul of a business. However, the file that contains the precious data for Outlook is a fragile one, and when it breaks it can be a nightmare to repair. Fortunately, plenty of tools out there can help keep the integrity of that data file intact. Which ones are the most reliable and safe to use? Which ones will bring the file back from the dead? Let's take a look at five that can effectively tackle the task.

Note: Always back up your data file before using any tool on it.

1: Built-in cleaner: Scanpst

Outlook has a built-in PST cleaner called Scanpst. It's not the tool you will use when a PST file is really broken, but it's one of the most reliable for smaller issues. I have used this tool more than any other, mostly because I know it won't completely fubar a PST file. You generally wind up having to run Scanpst more than once to get the data file completely clean. I've used it up to five times on a PST file before it will come up with zero errors. But it works.

2: Kernel Recovery for PST

Kernel Recovery for PST is the cleaner I use when the PST file is really broken. This tool is powerful and offers a number of features not found in other cleaners. One of my favorite features (although not unique) is the ability to split an overly large PST file into smaller archives. That alone makes this tool worth having. Beyond that, its ability to repair a severely broken PST file is unrivaled. You can download a demo of this tool, but you won't be able to do any repairing with it. Kernel Recovery for PST costs $49.00 (home use), $199.00 (corporate license), and $299.00 (technician license). It's worth the cost of entry.

3: Outlook PST Repair and Recovery Software

Outlook PST Repair and Recovery Software from Disk Doctors can quickly and safely recover the usual suspects from a damaged Outlook ST file: messages, folders, appointments, meeting requests, contacts, tasks, task requests, journals, and notes. This tool also supports the recovery of password-protected PST files, as well as compressed encryption and high encryption PST files. The one downfall of DD PST Repair is that it supports only Outlook 2000, 2002/XP, 2003, and 2007. A single user license for DD PST Repair costs $149.00.

4: Stellar Phoenix Outlook PST Repair

Stellar Phoenix Outlook PST Repair is an excellent tool that can repair even the most severely broken PST file. With it, you can repair corrupt PST files (Outlook 2000, 2003, 2007, and 2010) to recover emails, calendars, contacts, journals, and notes. It will also restore formatting from RTF and HTML messages, as well as repair damage from application malfunction, improper file sharing on LAN/WAN, operating system corruption, disrupted PST compaction, exceeded 2GB file size, PST file header corruption, and malicious software. Stellar Phoenix Outlook PST Repair costs $149.00 for a single license.

5: OutlookFIX Professional

OutlookFIX Professional is unique in that it will attempt to recover deleted information from the PST file. It does the usual cleanup (mail, attachments, calendar, tasks, contacts, journal, etc.) and works on most versions of Outlook (up to 2010). Of all the tools you will use, OutlookFix might well be the quickest and most user-friendly. It's not quite as powerful as Stellar or Kernel PST, but it's just as reliable. This is another PST repair tool that allows you to split the PST into multiple fragments. That means that any PST file over 2 GB can be reduced in size and cleaned up so the data can once again be used. OutlookFIX costs $179.00 for a single license.

Be ready

There are all sorts of reasons why an Outlook PST file can become corrupt. And when it happens, work stops. If you work within any size business that depends upon Outlook, chances are you will need the services of a PST repair tool. Don't get caught unaware. Have one on hand before the need arises.