Purpose of Files with the .pst File Extension

What is the .pst file extension?

The file extension .pst is recorded to be associated with Microsoft Outlook, a popular e-mail program from Microsoft. .pst files are data files and are commonly referred to as Outlook personal information store files.

Purpose of .pst files

.pst files are used for locally storing a user?s Outlook data, including e-mail folders, contact lists, and calendar entries. You can make .pst files password-protected to prevent unauthorized users from accessing the stored information.

Size limitations of a .pst file

In Outlook versions before 2003, the size of a .pst file is limited to 2 gigabytes. When a .pst file approaches its maximum limit, there is a significant drop in Outlook?s performance. In some cases, Outlook may freeze up when you click on any message or folder.

In Outlook 2003, better cushion is provided to users with increased .pst file size limits (20 gigabytes).

If you notice that a .pst file is approaching its maximum limit, then delete data from your folders and empty the Deleted Items Folder. Alternatively, you may use a tool named, Exchange 2000 Tool: PST2GB to reduce the size of a .pst file. As this tool truncates the .pst file, you may loose some data in the process. That is why it is recommended that you back up the .pst file before using PST2GB to reduce its size.

Names of the programs that can open .pst files

If you use Windows, you may open a .pst file using any of the following programs:

  • Microsoft Outlook
  • Microsoft Outlook Express

If you use a Mac operating system, you open a .pst file using the following program:

  • Microsoft PST Import Tool for Entourage

Other file types recorded using the .pst file extension

Various other file types are also known to use the .pst file extension, their names are:

  • BMail Postbox File
  • Ulead Pattern Image Format
  • MIDI Studio Preset File
  • Mastercam Post Processor File
  • LightWave 3D preset
  • Autodesk Structure Library Correlation File
  • Autodesk Structure Library Definition File
  • Autodesk Land Desktop Pipeworks Structural File
  • Medbasin Parameter File
  • Yamaha Pianist File
  • Lahey Fortan Paste Buffer

Help in opening .pst file types

In case you cannot open a .pst file type using the program installed on your Windows PC, then you may seek the assistance of a reliable third-party file extension repair software.