The recovery method depends on whether the missing folders are stored on the mail server or locally in an Outlook .pst file, so first check the same account in webmail.
1. Check whether the folders are online
Sign in to your email through its website—for example, Outlook.com or your email provider’s webmail—and inspect the folder list.
- Folders appear in webmail: They are server-hosted. In classic Outlook, verify that the account was added using the correct account type. For example, Outlook.com, Hotmail.com, and Live.com addresses should use Outlook.com, not Exchange or Microsoft 365. Outlook should then synchronize the existing folders.^1^
- Folders do not appear in webmail: They were probably stored locally on the old computer. Recover the
.pst file as described below.
- You no longer have the old computer or a backup containing the
.pst: Locally stored folders cannot be reconstructed from the new Outlook installation.
2. Recover locally stored folders from the old computer
On the old computer:
- Close Outlook.
- Open File Explorer and check:
C:\Users\<old-user-name>\Documents\Outlook Files
- Find files ending in
.pst. Windows 11 and current Outlook versions commonly store POP-account data there.^2^
- Copy—do not move—the
.pst file to an external drive. Retain the original until the restored folders have been verified.
- Copy it from the external drive to the new computer, preferably into:
C:\Users\<new-user-name>\Documents\Outlook Files
Do not copy an .ost file as a substitute. For Microsoft 365, Exchange, and Outlook.com accounts, an .ost is recreated when the account is added and cannot be transferred between computers.^2^
3. Open the recovered file in classic Outlook
- Open Outlook (Classic).
- Select File → Open & Export → Open Outlook Data File.
- Select the copied
.pst file.
- In the left Navigation pane, expand the newly added data-file heading.
- Expand its folders and confirm that the missing subfolders and messages are present.^3^
You can leave that file attached as a separate folder tree. If you want its contents in the current mailbox instead, move or import them only after verifying that the recovered file contains everything expected.
If this is an IMAP account
When the folders exist in webmail but remain absent from classic Outlook:
- Right-click the email account in Outlook’s folder pane.
- Select IMAP Folders.
- Locate each missing server folder and select Subscribe.
- Select OK, then allow Outlook to synchronize.^4^
If automatic account setup failed or used the wrong server details, obtain the correct account type and IMAP settings from the email provider, then use Change Account Settings while adding the account.^1^
References
- Troubleshoot Outlook email setup | Microsoft Support
- Find and transfer Outlook data files from one computer to another | Microsoft Support
- [Classic Outlook](https://support.microsoft.com/outlook/open-and-find-items-in-an-outlook-data-file-pst#open-an-outlook-data-file-in-classic-outlook)
- Missing folders after New Outlook installed - Microsoft Q&A