Import Emails From Outlook: PST and Account Options

To import emails into Outlook, use Outlook classic for Windows to import a Personal Folders file (.pst): choose File > Open & Export > Import/Export, then select Import from another program or file. If the messages are still on another email account, add that account to Outlook instead; importing a PST and connecting an account are different tasks.

What importing emails into Outlook means

People use “import emails from Outlook” to mean several things: bringing an old Outlook archive into a new installation, copying messages from another mailbox into Outlook, or moving Outlook data to a different computer. The right approach depends on where the messages are stored and whether you want a one-time copy or ongoing access to a mailbox.

A PST file is a portable Outlook data file that can contain email, folders, contacts, calendar items, and other Outlook data. It is often used for a backup or an archive. An OST file, by contrast, is generally a locally cached copy of an Exchange, Microsoft 365, or IMAP mailbox. It is tied to the account and Outlook profile that created it, so it is not normally a file you import into another profile. To move a mailbox, reconnect the account and let it synchronize, or use a supported export or migration method.

If your goal is simply to see older messages, you may not need to import them. Opening a PST lets you browse its folders alongside your current mailbox. Importing copies its contents into a selected mailbox or data file, which can make the messages easier to find in one place but may create duplicates.

Choose the method that matches the source

Outlook PST archive: Import it with Outlook classic for Windows, or open it as a separate data file if you want to keep the archive distinct.
Another active email account: Add the account to Outlook. IMAP and Microsoft-hosted accounts generally synchronize messages and folders rather than requiring a one-time file import.
Outlook on an old computer: If the mailbox is hosted by Microsoft 365, Exchange, Outlook.com, or an IMAP provider, adding the same account on the new computer usually downloads the mailbox again. If the old messages exist only in a local PST, transfer that PST securely and import or open it.
Mail exported from a different app: Check its export format. Outlook does not treat every archive format, such as an MBOX file, as a PST. You may need the original app, a provider migration tool, or a reputable conversion process.

Before moving anything, identify whether the source is an account, a PST, or another file type. A file ending in .csv is typically a table used for contacts, not a complete email archive.

Import a PST in Outlook classic for Windows

These steps apply to the classic Outlook desktop app included with Microsoft 365 on Windows. If Outlook has a New Outlook switch in its window and you are using the new app, switch back to classic Outlook if it is installed; its Import/Export wizard is the established route for PST imports. Menu availability can differ by account and build.

Copy the PST to a local folder you can access, such as Documents. If it came from a backup drive or another computer, make a separate backup copy before changing or moving the file.
Open classic Outlook and select File > Open & Export > Import/Export.
In the wizard, choose Import from another program or file, then select Outlook Data File (.pst).
Browse to the PST. Choose how Outlook should handle duplicate items: replace duplicates, allow duplicates, or do not import duplicates. The best choice depends on whether the destination already contains some of the archive.
Choose the folder to import. Select the PST’s top-level folder and enable Include subfolders to bring in its nested mail folders. Choose the destination mailbox or folder when prompted, then finish the wizard.

Allow time for a large archive to process. Afterward, check several folders, dates, and attachments rather than assuming that seeing the Inbox proves every folder transferred. If the import lands in the wrong place, the messages may still be present; expand the destination folders and search for a distinctive subject or sender.

If you want to keep the archive separate, use File > Open & Export > Open Outlook Data File and select the PST. Its folders appear in the folder pane, and you can copy individual messages or folders into the mailbox later. This is often preferable for a large historical archive because it avoids mixing old mail with current folders.

New Outlook and Outlook for Mac

New Outlook for Windows has a different interface from classic Outlook, and data-file features can vary by release. Do not assume that instructions for the classic Import/Export wizard apply to the new app. If a PST import option is not available in your version, open classic Outlook and perform the import there, then allow the mailbox to synchronize if the destination is a Microsoft 365 or Exchange mailbox. If classic Outlook is not installed, check Microsoft’s current support information for your build or use a supported migration route rather than renaming the file.

Outlook for Mac uses different menus and does not have the same Windows Import/Export wizard. In classic Outlook for Mac, import options are generally under File > Import; the available choices depend on the version and may include Outlook data files or an Outlook for Mac archive (.olm). New Outlook for Mac can have different import capabilities. Check the import choices in the installed version before preparing a file, and retain the original archive until you have verified the result. PST support and the treatment of calendar or contact data can differ from Windows.

For a mailbox hosted online, adding the account in the Mac app is usually simpler than exporting and importing its messages. The app can synchronize the account’s folders, subject to the provider’s server settings and the amount of mail retained online.

Connect another email account instead of importing

If messages are still on Gmail, Outlook.com, Microsoft 365, Exchange, or another provider, add that account to Outlook. In classic Outlook for Windows, use File > Add Account. In New Outlook for Windows, open Settings > Accounts > Email accounts and choose the option to add an account. The exact labels may change as Microsoft updates the interface. Sign in with the provider’s supported authentication; some organizations require administrator approval or additional security steps.

With IMAP, Outlook synchronizes mail folders with the server, so changes may appear in other mail apps too. Exchange and Microsoft 365 accounts also synchronize supported mailbox data, including more than just email. POP accounts behave differently: depending on the settings, messages may be downloaded to one device and may not remain available on the server. Confirm the provider’s settings before removing an account or deleting local mail.

Adding an account is not necessarily a permanent archive. If you need a standalone copy for records, export or back up the data using the provider’s supported method after confirming what it includes. A connected mailbox can also display only the mail retained by the service or allowed by its synchronization settings.

Contacts, calendars, and folders are different data

A PST may include contacts and calendar items as well as messages, but an import is not the same as importing a spreadsheet of contacts. A CSV file is a structured list of fields such as names and email addresses. In classic Outlook for Windows, contacts can be brought in through File > Open & Export > Import/Export, choosing the option to import from another program or file and then the CSV format. You may need to map the CSV columns to Outlook contact fields.

Calendar items also depend on the source format and destination. A PST can hold Outlook calendar folders; an ICS file is commonly used for calendar events, while a CSV contact file does not contain full email messages or calendar entries. Check the export’s contents and the import wizard’s options before expecting every type of data to move. Mail rules, account passwords, signatures, and some settings are not simply copied by importing messages.

Duplicates, missing mail, and other common problems

Duplicates are common when a PST overlaps with mail already synchronized from the same account. The wizard’s duplicate setting controls how it handles matching items during that import, but it cannot always identify messages that look similar yet differ in a meaningful way. For a clean move, test with a small archive or a separate destination first. Avoid repeatedly importing the same PST without checking the result.

The PST is not listed: Confirm the file is actually .pst, stored in an accessible folder, and not still inside a compressed ZIP archive. If it is password-protected, you need the password.
The import stops or reports an error: Make a backup, check that the file is not read-only or damaged, and try copying it to a local drive. Very large archives can take time; do not interrupt Outlook without a reason.
Some folders appear empty: Expand the folder tree, confirm that subfolders were included, and search the destination for a known message. Also check date filters and whether the original account had additional folders.
The mailbox fills up: Importing into a server mailbox can count toward its storage limit. Consider opening the PST as a separate archive or ask the organization’s administrator about mailbox capacity before merging a large file.

Protect the archive and verify the result

Email archives can contain sensitive personal, financial, or workplace information. Keep the PST in a protected location, use device encryption where available, and avoid uploading it to an unknown conversion website. A PST password can add a barrier but should not be treated as a substitute for secure storage or a backup. Follow workplace retention and data-handling rules when the mailbox belongs to an employer.

Keep the original file unchanged until you have confirmed that the destination contains the expected messages and attachments. Check older and newer dates, several nested folders, and a few large messages. If the archive is important, keep a second backup on separate, secure storage. An import is a copy operation, not proof that the source backup is valid.

Frequently Asked Questions

Can I import emails into Outlook without a PST?
Yes. If the emails remain in an online mailbox, add that account to Outlook and let it synchronize. For an export from another mail app, check the file format; Outlook may not import that format directly.

Can I import a PST into Outlook on the web?
Outlook on the web does not use the classic Windows Import/Export wizard to upload a PST. Use Outlook classic for a supported PST import, or connect the online account that holds the messages.

Should I import a PST or open it?
Open it when you want to browse an archive separately and keep your current mailbox unchanged. Import it when you want to copy its contents into selected folders or a mailbox, while taking care to avoid duplicates and storage-limit issues.

Will importing email also move my contacts and calendar?
It can if those items are included in the PST and you import the relevant folders, but email-only exports will not contain them. Contacts in CSV and calendar events in ICS are separate formats with separate import steps.

Why can’t I see the Import/Export option?
You may be using New Outlook, Outlook on the web, or a version with a different menu. The classic Windows wizard is available in Outlook classic; switch to that app if installed, or use the import options supported by your specific Outlook version.

Try it: the Date Difference Calculator: days, months, years and weekdays between two dates, with the DATEDIF formulas.

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