Outlook data files are the files in which your emails, calendars, contacts and other Outlook items are stored locally. There are two main types: PST and OST.
📂 Types of Outlook Data Files:
| File Type | Stands For | Use Case |
|---|---|---|
| .PST | Personal Storage Table | POP3 accounts, manual archiving, backup |
| .OST | Offline Storage Table | IMAP and Exchange accounts, offline access |
🔍 What is a PST File?
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It is used for POP3 accounts.
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Items such as emails, calendars and contacts are stored in this file.
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It is usually located in this folder:
C:\Users\<UserName>\Documents\Outlook Files -
It can be moved, backed up or archived manually.
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In Outlook, it is opened via File > Open & Export > Open Outlook Data File.
🔒 What is an OST File?
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It is created automatically for IMAP and Exchange accounts.
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It works in sync with the server and provides offline access.
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When Outlook reconnects, data is synchronized with the server.
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It is usually located in this folder:
C:\Users\<UserName>\AppData\Local\Microsoft\Outlook
