How to Backup Outlook Emails & Mailboxes from Desktop & Mail Servers?

  

Leena Taylor Paul   
Updated: May 19, 2026 • Backup • 9 Min Read

Why Back Up Outlook Emails?

Outlook stores years of mail, calendars, contacts, and tasks in PST and OST files. A ransomware attack, hard drive crash, or accidental deletion can erase all of it instantly. So the question isn’t whether you need a backup — it’s which method fits your setup.

Common reasons to backup Outlook emails:

Which Outlook Backup Method Should You Use?

First, identify where your Outlook data lives. Then pick the method that matches.

• Desktop Outlook (PST stored locally): Method 1 — Import/Export Wizard.
• Exchange Server (OST or online mailbox): Method 2 — contact your Exchange admin, or use the PST path if data is stored locally.
• Outlook.com web account (free or Microsoft 365): Method 3 — web export or add to desktop Outlook.
• Multi-account, scheduled, or bulk backup: Method 4 — dedicated Outlook backup tool.

Method 1: Export Outlook Desktop Emails to PST (Built-In Wizard)

The Import/Export Wizard is Outlook’s built-in backup tool. It exports your full mailbox — mail, contacts, calendar, tasks, and notes — to a single PST file you can store locally, on a drive, or in the cloud.

So use this method when you want a free, complete, one-time backup of a desktop Outlook account.

Step-by-Step: Export to PST with the Import/Export Wizard

• Open Outlook. Click the File tab, then click Open & Export.

• Click Import/Export to open the wizard.

• Choose Export to a File and click Next.

• Pick Outlook Data File (.pst) and click Next.

• Select the folder to export. To backup your entire mailbox, select the top-level account name and check Include subfolders. This way, you capture mail, contacts, calendar, notes, and tasks in one pass.

• Choose a destination path for the PST file. You can also change the filename from the default backup.pst. Then click Finish.

Also, note the path you saved to — you’ll need it if you want to restore later or open the PST on a new machine.

Alternative: Drag and Drop Emails to File Explorer

This is the fastest way to back up a single email or a small batch. Instead of a PST, each message saves as an MSG file you can open directly in Outlook.

• Open Outlook and File Explorer side by side.
• Select the emails you want to save.
• Drag them from Outlook into the File Explorer folder.

Double-clicking any saved MSG file opens it in Outlook. However, note that this method doesn’t back up attachments separately — they stay embedded in the MSG file.

Save Emails as HTML, MHT, or TXT

If you want a readable archive rather than a restorable backup, you can save individual emails as HTML, MHT, or plain text files.

• Open the email you want to save.
• Click File > Save As.
• Choose a file type from the Save as type dropdown: HTML, MHT, or TXT.

Note: this method doesn’t save attachments. You need to download those separately.

Forward Emails to Another Account

For a quick one-off backup of a specific message, forward it to another email address you control.

• Open the email in Outlook.
• Click Forward in the ribbon.
• Type the destination email address and send.

Method 2: Backup Outlook Emails for Exchange Server Users

If your Outlook connects to an Exchange Server, the mailbox lives on the server — not on your local PC. So your Exchange admin typically handles backups at the server level.

However, you can still check where your data lives and act accordingly.

• Open Outlook. Click File > Info > Account Settings > Account Settings.
• Open the Data Files tab.

• If the file shows an OST extension or says “Online” — your data is on the Exchange Server. Contact your admin to backup the mailbox.
• If the file shows a PST extension — the data is stored locally. In that case, follow Method 1 to backup that PST.

For Microsoft 365 bulk backup across multiple users, admins can use PowerShell with the Exchange Web Services (EWS) API or the Microsoft Graph API. For most users though, a dedicated backup tool (Method 4) is the practical option.

Method 3: Backup Outlook.com Emails

Outlook.com is Microsoft’s free web email service (formerly Hotmail). It also covers Microsoft 365 personal subscriptions. There are two ways to back up your Outlook.com mailbox.

Backup Outlook.com via the Web Interface

This method exports your entire mailbox. Note that selective email backup isn’t possible through the web interface — it’s all or nothing.

• Go to Outlook.com and sign in. Click the gear icon and choose View all Outlook settings.

• Go to General > Privacy and data.

• Click Export mailbox. Outlook.com prepares the backup and emails you a download link within about four days.

If you don’t receive the link after four days, return to the same Privacy and data section — the download link appears there directly.

Backup Outlook.com via Outlook Desktop App

If you have Outlook 2016 or later installed, you can add your Outlook.com account and then use the Import/Export Wizard from Method 1 to back up the mailbox locally.

• Open Outlook desktop. Go to File > Info > Add Account. Enter your Outlook.com email address and click Connect.

• Enter your password and click Next. Outlook connects and syncs your mailbox.

• Once the account syncs, follow Method 1 (Import/Export Wizard) to export the mailbox to a PST file.

Method 4: Use a Dedicated Outlook Backup Tool

Manual methods work for one-off backups, but they don’t scale. A dedicated tool lets you backup Outlook emails from web accounts (Outlook.com, Microsoft 365), apply date or folder filters, schedule automated runs, and export to multiple formats.

For example, Email Bakup supports Outlook web accounts, Exchange, and Microsoft 365 directly — no PST file required as an intermediate step.

Common Outlook Backup Errors and Fixes

Import/Export wizard missing in Outlook 365

The wizard hides for some shared mailbox views. To fix it, switch to the primary account under File, Account Settings before running the backup.

PST export fails at 90% with “data file integrity” error

A corrupt message is blocking the export. First, run scanpst.exe against the source PST file, then retry the export.

PowerShell EWS script returns “Throttled”

Microsoft 365 enforces strict throttling on bulk EWS requests. Lower concurrent threads to 2, add a 5-second sleep between mailboxes, and run during off-peak hours.

Backup tool reports “MAPI subsystem unavailable”

Outlook is either not installed or the wrong bitness. Install Outlook with matching architecture (32-bit Outlook needs 32-bit MAPI), then retry.

Frequently Asked Questions

Does Microsoft automatically back up my Outlook 365 mailbox?

No. Microsoft replicates mailboxes for availability, but doesn’t provide user-driven backups. So you must export to PST manually or use a third-party backup tool to keep a personal copy.

How often should I backup Outlook emails?

Daily for business mailboxes, weekly for personal use. Dedicated tools support automated incremental backups overnight so you don’t have to remember.

What is the largest PST file Outlook supports?

Unicode PST supports up to 50 GB in Outlook 2010 and later. In fact, older ANSI PST files cap at just 2 GB. If your mailbox exceeds 50 GB, split the export by folder or date range.

Can I backup Outlook 2019 the same way as Outlook 365?

Yes. The Import/Export Wizard works identically in Outlook 2016, 2019, and Microsoft 365. Steps and menu locations are identical across all three versions.

Can I backup shared mailboxes and public folders?

Yes. Add the shared mailbox as a secondary account in Outlook, then run the Import/Export Wizard with that mailbox as the source. Public folders need a separate PowerShell export or a dedicated backup tool.

How do I backup Outlook emails from a browser without the desktop app?

Use the Outlook.com web export method (Method 3A above). Sign in at Outlook.com, go to Settings, General, Privacy and data, then click Export mailbox. You’ll receive a download link within four days.