Old Emails Missing on a New PC? Export and Import PST Files

Why old emails are missing on a new computer

Whether your old mail follows you depends on how your email account connects to Outlook.

Microsoft's guide to finding and transferring Outlook data files puts it plainly: with a POP account, all your information is stored in a Personal Folders (.pst) file, and you can move that file to a new computer. For Microsoft 365, Exchange and Outlook.com accounts, mail is on the server and you usually have no PST at all, only an .ost cache that Outlook rebuilds by itself.

Many Singapore small businesses still run email from their web host (cPanel or similar) set up as POP years ago. If that is you, the old PC is currently the only copy of your email history. Do not wipe or return it until the export is done.

Find the PST file on the old PC

Start on the old computer, with classic Outlook installed (the version with a File tab at the top left).

• In classic Outlook, go to File > Account Settings > Account Settings > Data Files. The list shows every data file and its full location.
• On Windows 10 and 11 the usual location is C:\Users\<your name>\Documents\Outlook Files, per Microsoft's data file guide.
• Older setups may store it under AppData. Turn on hidden files in File Explorer if you cannot see the folder.
• If you see more than one PST (for example an archive file), note all of them. Each one needs copying.

Copying the existing PST file straight across, with Outlook closed, is often the quickest route for a POP account. Exporting to a fresh PST, below, is cleaner when the old file is very large or you only want some folders.

How to export Outlook email to a PST file

These are the classic Outlook steps from Microsoft's export to a .pst file article.

1. 1

   Download all mail first (IMAP and Microsoft 365)

   Outlook downloads only the past year by default for some accounts. Go to Account Settings, select the account, and move the sync slider to All before exporting, or older mail will be missing from the file.

2. 2

   Open the Import/Export wizard

   In classic Outlook, choose File > Open & Export > Import/Export, then Export to a file > Next.

3. 3

   Choose Outlook Data File (.pst)

   Select Outlook Data File (.pst) and Next. Then pick the email account to export; only one account can be exported at a time.

4. 4

   Include subfolders

   Tick Include subfolders so Inbox, Sent, Calendar, Contacts and Tasks all come across, then choose Next.

5. 5

   Save it outside OneDrive

   Browse to a local folder or USB drive and give the file a clear name. Microsoft says OneDrive blocks automatic syncing of .pst files, so do not save it there.

6. 6

   Finish and set a password if asked

   Choose Finish. Outlook may offer an optional password for the new file; if you set one, store it in your password manager.

Copy the finished file to the new PC by USB drive or external disk. A PST holds your full email history, including attachments, so treat that drive as confidential and wipe it afterwards.

How to import a PST file into Outlook on the new PC

Microsoft's import from a .pst file article covers both versions of Outlook. Set up your email account on the new PC first.

Classic Outlook

1. Go to File > Open & Export > Import/Export.
2. Choose Import from another program or file, then Outlook Data File (.pst).
3. Browse to the PST, choose how to handle duplicates, and enter the file password if there is one.
4. Pick the destination: your mailbox if you want the mail on the server, or the current folder.
5. Choose Finish. When the progress box disappears, the import is done.

New Outlook for Windows

Microsoft's import article now lists Settings > Data files > Import in new Outlook, and its feature comparison (updated June 2026) says new Outlook can import mail, calendar events, contacts and tasks. Some other Microsoft pages still say PST import needs classic Outlook, so if you do not see the option on your build, switch back to classic Outlook for the import.

What a PST import does not bring across

Microsoft says a PST export includes attachments and copies your mail, contacts and calendar, but not folder properties such as views, permissions and AutoArchive settings, message rules or blocked senders lists. Plan to redo these by hand:

Do not leave the import as the only copy. Keep the PST on an encrypted external drive until you have checked that the imported mail opens on the new PC, then decide how long to keep it.

The long-term fix: move to a cloud mailbox

A PST is a single file on a single disk. If the PC is stolen, the disk fails or ransomware hits, that mail is gone, and every new laptop means another export. Moving to Microsoft 365 or Google Workspace puts the mailbox on the server, so any device you sign in on shows the full history.

If your mail is on cPanel hosting today, our guide to moving cPanel email to Microsoft 365 shows the full move, and migrating between Google Workspace and Microsoft 365 covers moves between the two. A cloud mailbox is not a backup on its own, though; see our guide to backing up Microsoft 365 and Google Workspace.

Do it yourself or get help?

Exporting and importing one PST is a job most people can do in under an hour, plus copying time for a large file. Get help if the old PC will not start, the PST reports errors, you have several staff to move, or you want to stop using POP for good.

A Quick Fix (1 hour) (S$119) covers moving one person's PST to a new PC and checking signatures and rules. Email Migration (S$390) moves your business onto Microsoft 365 or Google Workspace, including importing old mail, so new PCs never start empty again.