How to Make New Outlook Use Classic Outlook PST Files via Import

You have an Outlook data file, also called a PST file, that was created in classic Outlook. You want to open that PST file in new Outlook for Windows so you can access your old emails, contacts, and calendar items. New Outlook does not support mounting PST files directly the way classic Outlook does. This article explains how to import a PST file into new Outlook so all your data becomes available in the new mail profile.

The import process copies the contents of the PST file into the online mailbox or into new Outlook’s local storage. After the import, you can delete the original PST file if you no longer need it. This guide covers the exact steps for importing a PST file into new Outlook and what to do if the import fails.

What a PST File Is and Why New Outlook Can’t Mount It Directly

A PST file, short for Personal Storage Table, is the data file format used by classic Outlook for Windows to store emails, calendar items, contacts, tasks, and notes. Classic Outlook can open a PST file as an additional mailbox in the folder pane. You can drag items between the PST and your main mailbox.

New Outlook for Windows, also called the One Outlook client, uses a different storage architecture. It relies on Microsoft 365 cloud storage or local Exchange Online cache. It does not have a folder pane that can mount a PST file as a separate store. Instead, new Outlook offers an import feature that reads the PST file and copies its contents into the current mailbox or into a dedicated local folder structure.

The import process preserves folder hierarchy, message dates, attachments, and metadata. After the import, the PST file remains unchanged. You can keep it as a backup or delete it after verifying that all data transferred correctly.

Steps to Import a PST File into New Outlook

You can start the import from inside new Outlook or by opening the PST file directly from File Explorer. Both methods lead to the same import wizard.

1. Open new Outlook and go to Settings
   Click the gear icon in the top-right corner of new Outlook. The Settings pane opens on the right side of the window.
2. Select General and then Import
   In the Settings pane, click General. Scroll down and click Import. The Import wizard opens.
3. Choose the PST file to import
   Click Browse and navigate to the PST file on your computer. Select the file and click Open. The file path appears in the import dialog.
4. Select the import destination
   You have two options: Import to current mailbox or Import to local storage. Choose Import to current mailbox if you want the data to appear in your primary mailbox folders. Choose Import to local storage if you want the data stored locally on this computer only, not synced to the cloud.
5. Start the import
   Click Import. New Outlook begins copying the data. The time depends on the PST file size. A 2 GB PST file may take 5 to 15 minutes. Do not close Outlook during the process.
6. Verify the imported data
   After the import finishes, go to the folder pane. Look for a new folder named Imported or for the original PST folder names nested under your mailbox. Expand the folders and confirm that emails, contacts, and calendar items appear.

If you prefer to start the import from File Explorer, locate the PST file, right-click it, select Open with, and choose Outlook (new). New Outlook launches and opens the same Import wizard with the PST file already selected. Proceed with steps 4 through 6 above.

What to Do If the Import Fails or Data Is Missing

PST file is password-protected and the import asks for a password

Classic Outlook allows you to set a password on a PST file. If the PST file has a password, the import wizard prompts for it. Enter the password exactly as set in classic Outlook. Passwords are case-sensitive. If you forgot the password, you cannot import the data. No recovery tool exists for PST passwords.

Import button is grayed out

The import button becomes active only after you select a valid PST file. If the button remains gray, the file may be corrupted or in use by another program. Close classic Outlook if it is running. Restart new Outlook and try again. If the issue persists, copy the PST file to a different folder and try importing from that location.

Data appears but some folders are missing

New Outlook imports the folder structure from the PST file. If you see fewer folders than expected, the PST file may have been exported with only specific folders selected. Open the PST file in classic Outlook to verify the original folder list. If classic Outlook shows all folders, delete the imported data in new Outlook and run the import again. To delete imported data, right-click the Imported folder and select Delete.

Import takes too long or seems stuck

Large PST files, especially those over 10 GB, can take 30 minutes or longer to import. Check the Outlook status bar for a progress indicator. If the progress bar does not move for 10 minutes, close new Outlook and restart it. The import resumes from where it stopped. If the progress bar still does not move, the PST file may be damaged. Run the Inbox Repair Tool (Scanpst.exe) on the PST file before importing again. The tool is located in the classic Outlook installation folder, typically C:\Program Files\Microsoft Office\root\Office16\SCANPST.EXE.

Import from PST vs Import from Classic Outlook Profile: Key Differences

Item	Import from PST File	Import from Classic Outlook Profile
Data source	Standalone PST file on disk	Live classic Outlook profile with connected mailboxes
Requires classic Outlook installed	No	Yes
Preserves folder hierarchy	Yes	Yes
Imports all data types	Emails, contacts, calendar, tasks, notes	Same as PST import
Best for	Single PST file from backup or archive	Migrating from a fully configured classic Outlook profile

After the import completes, you can safely delete the original PST file. Open new Outlook and verify that all data is accessible. If you plan to keep using classic Outlook alongside new Outlook, do not delete the PST file until you are certain you will not need it again.

For advanced users, new Outlook also supports importing from a classic Outlook profile directly. Go to Settings > General > Import and select From another Outlook profile. This method copies all data from the classic Outlook profile without needing to locate the PST file manually.