If you have used classic Outlook for Windows for years, you likely rely on PST files to archive emails, back up data, or move mail between computers. In the new Outlook for Windows, Microsoft changed how local data files are handled. This article explains where PST files are stored in new Outlook, how to open them, and which features still differ from the classic version. You will learn the exact folder paths, the limitations of PST support, and what to do when a feature is missing.
Key Takeaways: PST File Location and Feature Gaps in New Outlook
- File > Open & Export > Open Outlook Data File: Opens any PST file from any location, but the file is not permanently attached to your profile
- %LocalAppData%\Microsoft\Outlook: Default folder where new Outlook stores PST files when you import or create an archive
- File > Account Settings > Account Settings > Data Files: Not available in new Outlook — you cannot view or manage PST attachments from this menu
Why New Outlook Handles PST Files Differently
New Outlook is built on a cloud-first architecture. Microsoft designed it to work primarily with Microsoft 365 and Exchange Online mailboxes. PST files are a legacy format that stores data locally on your computer. Because new Outlook syncs most data from the cloud, it treats PST files as temporary imports rather than permanent profile components.
In classic Outlook, a PST file is attached to your mail profile and appears as a separate folder tree in the navigation pane. You can drag messages between the PST and your mailbox. The PST remains available every time you start Outlook. In new Outlook, you can open a PST file to view its contents, but the connection is not persistent. You must reopen the PST file each time you restart Outlook. This is the most important difference to understand.
Where PST Files Are Stored by Default
When you create a new PST file in new Outlook using the Export or Archive feature, the file is saved in the same default location as classic Outlook:
%LocalAppData%\Microsoft\Outlook
On most Windows 11 and Windows 10 systems, this expands to:
C:\Users\[YourUsername]\AppData\Local\Microsoft\Outlook
If you import a PST file from another location, new Outlook copies the file to this folder. The original file remains unchanged. You can also open a PST file directly from any folder on your computer without moving it.
Steps to Open a PST File in New Outlook
The process to open a PST file in new Outlook is similar to classic Outlook, but the result is temporary. Follow these steps:
- Open new Outlook
Launch the new Outlook for Windows application. Ensure you are signed in with your Microsoft 365 or Outlook.com account. - Go to File > Open & Export
Click the File tab in the ribbon. In the left pane, select Open & Export. - Select Open Outlook Data File
Click the Open Outlook Data File option. A standard file browser dialog opens. - Browse to the PST file
Navigate to the folder containing your PST file. The default location is %LocalAppData%\Microsoft\Outlook. Select the file and click Open. - View the PST contents
The PST file appears as a new folder at the bottom of the navigation pane. You can expand folders, read messages, and search within the PST. The file remains available until you close new Outlook.
After you close and reopen new Outlook, the PST file is no longer visible. You must repeat steps 2 through 5 to access the data again.
How to Keep a PST File Visible Permanently
New Outlook does not support persistent PST attachment to your profile. There is no setting to make a PST file automatically appear on startup. If you need permanent access to old PST data, you have two options:
- Use classic Outlook for Windows to attach the PST file permanently. Classic Outlook allows you to add a PST file through File > Account Settings > Account Settings > Data Files > Add.
- Import the PST data into your Microsoft 365 mailbox. Use the Import feature in new Outlook to copy all messages, contacts, and calendar items from the PST into your online mailbox. After the import completes, the data is available from any device.
What Still Differs Between Classic and New Outlook for PST Files
Several PST-related features available in classic Outlook are missing or work differently in new Outlook. These differences affect how you manage archived email and local data.
No Permanent PST Attachment
As described above, classic Outlook lets you attach a PST file to your mail profile. The PST appears as a top-level folder every time you start Outlook. New Outlook only opens PST files temporarily. You cannot add a PST to your profile permanently.
No Data Files Management Dialog
In classic Outlook, you can view all attached PST files and their properties through File > Account Settings > Account Settings > Data Files. This dialog shows the file path, size, and format for each PST. New Outlook does not include this dialog. You cannot see a list of opened PST files or check their properties from within the application.
No AutoArchive
Classic Outlook includes an AutoArchive feature that automatically moves old items to a PST file based on aging rules. New Outlook does not support AutoArchive. You must manually export or archive data using File > Open & Export > Import/Export.
No PST Compression or Repair Tool
Classic Outlook includes the Scanpst.exe tool to repair corrupted PST files and a compact now feature to reduce PST file size. New Outlook does not provide these tools. If a PST file becomes corrupted, you must use the classic Outlook Scanpst.exe tool or a third-party repair utility.
PST File Size Limit Applies
Both classic and new Outlook enforce the same PST file size limit. For PST files created in Outlook 2003 and later, the default limit is 20 GB for Unicode format. New Outlook does not allow you to increase this limit. If your PST file exceeds 20 GB, you must split the data into multiple PST files or archive older items.
Classic Outlook PST Features vs New Outlook PST Features
| Item | Classic Outlook | New Outlook |
|---|---|---|
| Permanent PST attachment | Supported | Not supported |
| Data Files management dialog | Available | Not available |
| AutoArchive | Supported | Not supported |
| PST repair tool (Scanpst.exe) | Included | Not included |
| PST file size limit | 20 GB (Unicode) | 20 GB (Unicode) |
| Open PST from any folder | Supported | Supported |
| Import PST data to mailbox | Supported | Supported |
If You Cannot Find a PST File in New Outlook
If you opened a PST file in new Outlook and it disappeared after restarting, you did not lose the data. The PST file remains in its original folder on your computer. Open new Outlook again and follow the steps in the section above to reopen the file.
The PST File Does Not Appear in the Navigation Pane
If you opened the PST file but do not see it in the navigation pane, check the following:
- Scroll to the bottom of the navigation pane. The PST folder appears below your primary mailbox and any shared mailboxes.
- Ensure the PST file is not corrupted. Try opening the same PST file in classic Outlook. If classic Outlook cannot open it either, use Scanpst.exe to repair the file.
- Verify the file extension is .pst. New Outlook does not support .ost files or .pst files created by older Outlook versions (97-2002 format).
New Outlook Cannot Open a PST File from a Network Drive
New Outlook may fail to open PST files stored on a network drive or external USB drive. Copy the PST file to your local hard drive first, then open it from the local folder. The default %LocalAppData%\Microsoft\Outlook folder is the safest location.
New Outlook Shows an Error When Opening a PST File
If you see an error message such as Cannot open this Outlook Data File or The file is not a valid Outlook Data File, the PST file may be corrupted or in an unsupported format. Try opening the file in classic Outlook first. If classic Outlook opens it successfully, export the data to a new Unicode PST file using File > Open & Export > Import/Export > Export to a file > Outlook Data File (.pst). Then open the new PST file in new Outlook.
Now you know where PST files are stored in new Outlook and how to open them. The key difference is that new Outlook does not attach PST files permanently to your profile. Use the Import feature to move data into your cloud mailbox if you need constant access. For advanced PST management like repair or compression, switch back to classic Outlook and use the Scanpst.exe tool located in the Program Files folder.