How to import PST to Outlook (classic, new Outlook, Outlook.com)

To import PST to Outlook, open classic Outlook for Windows and run File → Open & Export → Import/Export → Import from another program or file → Outlook Data File (.pst), browse to the file and choose where the items go. If you only need to read the PST, File → Open & Export → Open Outlook Data File attaches it as a folder tree without copying anything. Below: both paths, the new Outlook and Outlook.com cases, moving a PST to a new computer, and what to do when the import fails.

Import or open: two ways to get a PST into Outlook

Outlook offers two different things and people mix them up. Importing copies the PST's items into your existing mailbox, so they sync to the server and show up on your phone. Opening attaches the PST as a separate, local folder tree: nothing is copied, the file stays where it is, and the mail is visible only on that PC.

Background on the format is in the PST file explainer; viewers for a PC without Outlook are on opening a PST file.

Have the email as a file (EML, MSG, MBOX)? Convert it to PDF in your browser: nothing is uploaded.

Import PST to Outlook step by step

1. Copy the .pst to the local disk (Documents\Outlook Files is the usual place). Do not import from a USB stick or a OneDrive folder.
2. In classic Outlook: File → Open & Export → Import/Export.
3. Choose Import from another program or file → Outlook Data File (.pst) → Browse to the file.
4. Pick the duplicate rule. Do not import duplicates is the safe choice when restoring a backup into a mailbox that already has part of the mail.
5. Select the folder to import from (the top item for everything), tick Include subfolders, and choose Import items into the same folder in your account, or into the current folder if you want them kept apart.
6. Finish. Outlook copies the items; for a large PST this takes a while and the progress bar is the only sign of life.

If the PST is password-protected you are asked for the password first. Contacts and calendar items come along when you import from the top folder.

New Outlook, Outlook.com and Outlook on the web

The new Outlook for Windows did not launch with PST import; Microsoft has been adding it, and the option appears under the account settings or import menu when your build has it. If it is missing, flip the toggle in the top right to classic Outlook, import there, and switch back: the items are in your account either way once they sync.

Outlook.com and Outlook on the web have no PST import at all. The way in is desktop Outlook with the Outlook.com or Microsoft 365 account added: open or import the PST there, drag folders into the account, and the server receives them. The same trick moves PST mail into a Gmail account; see importing a PST to Gmail.

Move an Outlook PST file to a new computer

For a POP account or an archive PST, the file itself is the mailbox. Close Outlook on the old PC, copy the .pst from its folder (File → Account Settings → Data Files shows the path) to the new PC's Documents\Outlook Files, then use Open Outlook Data File or run the import. For Exchange, Microsoft 365 and IMAP accounts you do not need to move anything for the live mail; it downloads again after sign-in. Only archive PSTs need copying.

Moving a PST is also the moment to check the file: open it on the new PC before deleting the old copy, and confirm a few folders and attachments.

Can't import a PST file into Outlook: common causes

• File in use. Another Outlook instance or a backup program has it open. Close everything and retry.
• Read-only. A PST copied from a CD or an external drive may carry the read-only flag; clear it in the file's Properties.
• Damaged file. Run SCANPST.EXE (the Inbox Repair Tool, in the Office program folder) on the PST, then retry.
• Old ANSI format. PSTs from Outlook 2002 and earlier are a different format; current Outlook still opens them but import can fail on size. Open the file instead and drag the folders.
• Empty or truncated file. A 265 KB or 0 KB PST is a container with nothing inside, usually from an interrupted export.
• Wrong Outlook. New Outlook without the import option, or Outlook for Mac, which imports PST through its own File → Import, not the Windows wizard.

Other clients, and a PDF copy of what matters

Some mail programs import PST on their own: eM Client on Windows has Menu → File → Import → Microsoft Outlook, and Outlook for Mac imports PST via File → Import. Thunderbird and Apple Mail do not; for them the PST goes through Outlook or a converter first.

Whichever way the mailbox ends up, the threads you may have to show someone are safer as PDFs than inside any mailbox file. Drag them out of Outlook as .msg files and convert them on MSG to PDF: headers including Message-ID at the top, attachments listed and downloadable, nothing uploaded. The guide to converting a PST to PDF covers the batch options when it is a whole mailbox.

Frequently asked questions