.PST File Extension

Outlook Personal Information Store

Developer Microsoft
3.3  |  71 Votes

What is a PST file?

A PST file is a data storage file that contains personal information used by Microsoft Outlook and Exchange. It may also include e-mail folders, contacts, addresses, and other data.

More Information

PST files have a 2 GB limit and will cause Outlook to slow down when the file is close to the limit. Microsoft provides a program called the Exchange 2000 Tool: PST2GB that will reduce the file size of a PST file. However, the utility may truncate the file meaning some data will be lost, so you should make sure to back up the PST file first.

Unlike the full version of Outlook, Outlook Express does not use PST files. However, Outlook Express can import PST data using the program's Import feature. Mac users can use the PST Import Tool for Entourage to import PST data into Entourage or the PST to MBOX Converter to convert PST files to .MBOX files.

Open over 400 file formats with File Viewer Plus.Free Download

Programs that open or reference PST files

Verified by FileInfo.com

The FileInfo.com team has independently researched the Outlook Personal Information Store file format and Mac and Windows apps listed on this page. Our goal is 100% accuracy and we only publish information about file types that we have verified.

If you would like to suggest any additions or updates to this page, please let us know.