How to Create a PST File in Outlook: A Complete Guide
A PST file (Personal Storage Table) is Outlook's local archive format — a single file on your computer that stores emails, contacts, calendar entries, tasks, and notes. Knowing how to create one gives you control over your email data: archiving old messages, backing up your inbox, or moving mailbox content between machines.
Here's exactly how it works, and what determines whether the process goes smoothly for your setup.
What Is a PST File and Why Create One?
When Outlook connects to an Exchange, Microsoft 365, or IMAP account, your messages typically live on a server. A PST file changes that equation — it stores data locally on your hard drive, independent of any server connection.
Common reasons to create a PST:
- Archiving old emails to free up server mailbox space
- Backing up your inbox before switching computers or reinstalling Windows
- Exporting mailbox data to move it to another Outlook profile or account
- Offline access to emails without a live server connection
PST files use the .pst extension and can grow to several gigabytes depending on how much mail they contain. Outlook supports a maximum PST file size of 50 GB in modern versions, though performance can degrade well before that ceiling.
How to Create a New PST File in Outlook (Windows) 📁
The method varies slightly depending on your Outlook version, but the core steps are consistent across Outlook 2016, 2019, 2021, and Microsoft 365 desktop.
Method 1: Create a New Data File Directly
- Open Outlook and click the File tab in the top-left corner
- Select Account Settings, then click Account Settings again from the dropdown
- Navigate to the Data Files tab
- Click Add
- Choose a location on your computer and give the file a name
- Click OK
Outlook creates a new, empty PST file and adds it as a folder in your left-hand navigation pane under the name you assigned. You can then drag and drop emails into it or set it as a delivery location.
Method 2: Export to a PST File
If your goal is to archive existing mail rather than create an empty file:
- Go to File → Open & Export → Import/Export
- Select Export to a file and click Next
- Choose Outlook Data File (.pst) and click Next
- Select the folders you want to export (you can include subfolders)
- Choose a save location and filename
- Click Finish
You can optionally set a password on the PST during this step — useful if the file contains sensitive data.
Key Variables That Affect the Process
Creating a PST isn't always a one-size-fits-all operation. Several factors shape how it works for any given user.
Account Type
| Account Type | PST Support | Notes |
|---|---|---|
| Microsoft 365 (Exchange) | Limited by admin policy | IT admins can restrict local PST creation |
| IMAP (Gmail, Yahoo, etc.) | Generally supported | Full export/archive available |
| POP3 | Fully supported | PST is the default local storage format |
| Outlook.com (personal) | Supported via desktop app | Not available through browser |
If you're on a corporate Microsoft 365 account, your IT administrator may have disabled the ability to create or use PST files through Group Policy. In that case, the options may be greyed out or simply absent — not a bug, but a deliberate restriction.
Outlook Version and Platform
PST files are a Windows-only feature. Outlook for Mac uses a different format (OLM files) and does not natively support PST creation or import in the same way. If you're on a Mac, the workflow is fundamentally different.
On Windows, the PST option is available in all modern Outlook versions (2016 and later), including the Microsoft 365 subscription version. The newer Outlook for Windows (the rebuilt version Microsoft has been rolling out) has limited PST support compared to the classic desktop app — a meaningful distinction if you've recently updated.
File Location and Storage
Where you save your PST matters. Storing a PST on a network drive or cloud-synced folder (like OneDrive or Dropbox) is not recommended by Microsoft — it can cause file corruption. PST files are designed for local storage on an internal or directly attached external drive.
Managing PST Files After Creation 🗂️
Once created, a PST behaves like any other folder group in Outlook. You can:
- Open an existing PST via File → Open & Export → Open Outlook Data File
- Close a PST by right-clicking it in the folder pane and selecting "Close"
- Move or copy it like any other file when Outlook is closed
- Compact it (reduce file size after deletions) via Account Settings → Data Files → Settings → Compact Now
PST files do not self-clean. Deleted items sent to the PST's Deleted Items folder stay there until manually purged, continuing to consume disk space.
Where Individual Setups Diverge
The steps above work cleanly for most personal and small-business Outlook users on Windows using classic Outlook with a POP3 or IMAP account. But the experience shifts depending on your specific combination of:
- Which Outlook version you're running (classic vs. new Outlook for Windows)
- Whether your account is managed by an organization with policy restrictions
- Your operating system (Windows vs. Mac)
- Your intended use — archiving, backup, migration, or offline access each suit slightly different approaches
- How much data you're working with, which affects export time and file management
The right approach for archiving 10 years of corporate Exchange mail looks quite different from creating a simple backup of a personal Gmail account connected via IMAP.