How to back up and restore your Outlook email data locally

Summary

This guide helps you troubleshoot and resolve: How to back up and restore your Outlook email data locally. Follow the steps below to fix the issue.

Common Causes

Backing up your Outlook mailbox to a local PST file is one of the most reliable ways to protect your emails, contacts, and calendar items. Whether you're preparing for a hardware upgrade, migrating to a new computer, or simply want a safety net before making changes, this guide walks you through exporting and restoring your Outlook data on Windows. The process differs slightly depending on whether you're using the classic Outlook desktop client or the new Outlook for Windows.

Before You Begin

Before exporting your mailbox, take a moment to confirm a few things:

• Identify which version of Outlook you're using. Open Outlook and check the title bar. If it says Outlook (new) or shows a toggle for Try the new Outlook, you're on the new version. Otherwise, you're using classic Outlook.
• Decide where you want to save the backup. A secondary drive, external USB, or network share is ideal. PST files can grow large (up to 50GB in modern Outlook), so ensure you have ample space.
• Close any other applications that might be accessing Outlook, such as OneDrive sync clients or third-party add-ins.
• Note that this guide covers Windows. Outlook for Mac uses a different export process (Archive to OLM file) and is not covered here.

Export Your Mailbox to a PST File (Classic Outlook)

1. Open classic Outlook and click File in the top-left corner.
2. Select Open & Export, then choose Import/Export.
3. In the wizard that appears, select Export to a file and click Next.
4. Choose Outlook Data File (.pst) and click Next.
5. Select the mailbox or folder you want to back up. To export everything, choose the top-level mailbox entry. Tick Include subfolders if available, then click Next.
6. Click Browse, choose a destination folder, give the file a meaningful name (such as Outlook-Backup-2024-11.pst), and click OK.
7. Choose whether to replace duplicates with exported items or allow duplicates, then click Finish.
8. If prompted, enter a password or leave the field blank and click OK. The export will begin and may take several minutes for large mailboxes.

Export Your Mailbox in the New Outlook for Windows

The new Outlook has limited built-in export options compared to classic Outlook. Use one of these alternatives:

Option A: Export from Outlook on the Web

1. Sign in to Outlook on the web using a browser.
2. Click the Settings gear icon, then select View all Outlook settings.
3. Go to General → Privacy and data.
4. Look for an option to export or download your mailbox data. Depending on your Microsoft 365 plan, this may be under Export mailbox or accessible via the Microsoft 365 admin centre.
5. Follow the prompts to request the archive. Microsoft will email you a link when the archive is ready (usually within a few hours).
6. Download the archive from the link provided and save it to your chosen location.

Option B: Use Classic Outlook Instead

If the new Outlook toggle is still available in your build, you can switch back to classic Outlook to perform the export:

1. In the new Outlook, look for the Try the new Outlook toggle (usually in the top-right corner). If it's enabled, toggle it off.
2. Follow the classic Outlook export steps above.
3. Once complete, you can switch back to the new Outlook if preferred.

Restore Your Mailbox from a PST File

1. Open classic Outlook.
2. Click File → Open & Export → Import/Export.
3. Select Import from another program or file and click Next.
4. Choose Outlook Data File (.pst) and click Next.
5. Click Browse, locate your backup PST file, and click Open.
6. Choose how to handle duplicates. Replace duplicates with items imported is usually safest for a true restore.
7. Select the folder you want to import. To restore the entire mailbox, choose the top-level entry. Tick Include subfolders and click Next.
8. Choose whether to import items into the same folder in your current profile or into a new folder. Click Finish.
9. Enter the password if the PST is password-protected.

Troubleshooting

The Import/Export option is missing

This usually means you're using the new Outlook. Switch back to classic Outlook using the toggle if available, or use the Outlook on the web export method described above.

The PST file won't open or shows errors

Run the built-in repair tool: close Outlook, then run scanpst.exe from your Office installation folder (commonly C:\Program Files\Microsoft Office\root\Office16\ for 64-bit or C:\Program Files (x86)\Microsoft Office\root\Office16\ for 32-bit installations). Point it at the damaged PST and let it complete the repair.

Export is very slow or hangs

Large mailboxes with many attachments can take considerable time. Try exporting individual folders rather than the entire mailbox, and ensure your laptop is plugged in and not running on battery saver mode.

Restored emails appear in the wrong account

When importing, ensure the destination account is correct in the wizard. If you have multiple accounts configured in Outlook, the import will target whichever account's profile you're currently using.

PST file is too large or approaching the size limit

Modern Outlook supports PST files up to 50GB. If your mailbox exceeds this, split the export into multiple PST files by exporting folders separately, or archive older items to an Online Archive mailbox if your Microsoft 365 plan supports it.

Keeping Your Backup Safe

• Store PST files on a drive separate from your operating system. If your hard drive fails, the backup fails with it.
• Consider copying the finished PST to an encrypted external drive or a secure cloud sync folder such as OneDrive for Business.
• Schedule regular exports. Monthly is a sensible baseline for most small businesses; weekly if your mailbox changes rapidly.
• Label each backup with the date in the filename so you can identify the most recent copy at a glance.

For related guidance on protecting other types of data, see our article on How to backup photos to external drive.

If you run into issues that aren't covered here, or you'd like one of our technicians to handle the backup or migration for you, Open a Ticket and we'll be happy to assist.

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