There are two types of Outlook Data Files used by Outlook. An Outlook Data File (.pst) is used for most accounts…. Outlook Data Files (.pst) are used for POP3, IMAP, and web-based mail accounts. When you want to create archives or back up your Outlook folders and items on your computer, such as Exchange accounts, you must create and use additional .pst files…. A Personal Folders file (.pst) is an Outlook data file that stores your messages and other items on your computer. This is the most common file in which information in Outlook is saved by home users or in small organizations…. 1
In Microsoft Outlook, the Personal Folders file (.pst) is a data file that stores all of a user’s messages and other items on his/her computer. An Outlook user can create one or more .pst’s to organize and back up items for safekeeping. Even when an e-mail system is being run on a Microsoft Exchange Server, Outlook data can be backed up to a .pst file stored either locally on a hard drive or on a network drive — rather than on the e-mail server. Each .pst file contains all of one’s Outlook folders, including the Inbox, Calendar, and Contacts. 2
The place where Outlook stores its data (when Outlook is used without Microsoft® Exchange Server). A PST file is created when a mail account is set up. Additional PST files can be created for backing up and archiving Outlook folders, messages, forms and files. The file extension given to PST files is .pst. 3
A MS Outlook mail container that requires extraction in order to be processed as mail messages and their attachments. 4
A file used in Outlook to save a collection of emails.