A new Outlook (file)

One of my colleagues called me recently when he was having trouble receiving e-mail. He uses Microsoft Outlook 2007, as I do. I asked whether he had checked the file integrity of his e-mail repositories using the appropriate diagnostic tool; he had never heard of it. I hope that the specific information below will help readers who have had similar problems with their Outlook e-mail client.

Outlook uses two kinds of data files for storing configuration parameters and e-mail: OST and PST files. Sometimes these files become corrupted; for example, if the client or the operating system crashes, certain pointers within the files may not be updated correctly. Although the damaged files may still be usable by the client software, the risk of unusual behavior or of further crashes increases.

One of the problems that I have encountered is that Outlook refuses to terminate its process when I close the client. The process holds its files open, preventing them from being backed up. If I terminate the process using the Windows XP Pro task manager, Outlook often reports that the PST file I use was not properly closed and goes through a brief (but not thorough) diagnostic and corrective routine upon reopening the file.

SCANPST.EXE is a diagnostic tool that comes with all Outlook installations. It handles both PST and OST files.

The program opens with a simple menu asking for the file that you wish to analyze (“Enter the name of the file you want to scan”). I’ve made it easy on myself to locate my PST files by entering the directory name into the “Start in” of a shortcut to the program. That addition then automatically opens the appropriate directory and shows all the Outlook files. Such a shortcut with directory information is particularly useful if you use the default location for your Outlook file; they are stored deep in hidden directories in your Windows “Documents and Settings” folder (e.g., C:\Documents and Settings\<userID>\Local Settings\Application Data\Microsoft\Outlook).

Once you click on “Start,” the program goes through nine phases which include the following: Initializing; Checking file consistency; then seven steps that go by so fast I’ve never seen their labels; and Checking folders and items. Finally, if you click on “Repair,” the program moves into its “Repairing” phase, during which it creates a backup copy (*.BAK or whatever you write in yourself) of your file and creates a new, presumably pristine file for further e-mail.

To give you a sense of the time involved, I measured how long it took to repair two damaged PST files on my main system - a dual-processor (2 x 3GHz) unit with 2GB of RAM and 7200-RPM disks with write-behind caching. Diagnosing and repairing my main 311MB PST file took 70 seconds for diagnosis and 40 seconds for the repair; a 1.2GB PST archive took 185 seconds for diagnosis and 475 seconds for repair. That’s about 0.17 sec/MB for diagnosis and about 0.34 sec/MB for repair, or roughly 0.5 sec/MB in all.

For more information about SCANPST.EXE, see the article “How to find and run the Inbox Repair tool in Outlook” from the Microsoft Knowledge Base. To locate your own SCANPST.EXE file, I suggest that you use the search capability of your operating system. If you cannot find it, you can download the appropriate version for your Outlook version by searching the Microsoft support site.

M. E. Kabay, PhD, CISSP-ISSMP, specializes in security and operations management consulting services and teaching. He is Chief Technical Officer of Adaptive Cyber Security Instruments, Inc. and Associate Professor of Information Assurance in the School of Business and Management at Norwich University. Visit his Web site for white papers and course materials.