How Does Outlook Handle Data?
PST files are your actual data containers (used for POP accounts, archives, etc.), and you can back them up directly to export Outlook to new computer.
The OST file, however, is just a local copy, or a cache, of your mailbox data that lives on the server (like in Microsoft 365, Exchange, or IMAP).
Because of this, you cannot restore or import OST to Outlook; if you need to create a backup of an OST mailbox, you have to export it to a PST first.
How to Back Up Outlook? (Manual Backup Methods)
The upcoming solutions include all the methods to back up Outlook manually without needing additional tools:
Method 1: Backup Outlook by Exporting as PST File
This is the official, built-in solution recommended by Microsoft. You can choose to back up: emails, calendar, contacts, and tasks while exporting a .pst file.
- Open Outlook and go to the File tab.
- Click Open & Export, then select Import/Export.
- In the wizard, choose Export to a file and click Next.
- Select Outlook Data File (.pst) and click Next.
- Select the Folder: To back up everything, select your email address at the very top of the list. Crucially, ensure the “Include subfolders” box is checked.
- Click Next.
- Choose a Location: Click Browse and save the file to a secure, easy-to-find location(e.g., your Documents folder).
Limitations
- When manually exporting a PST file, you have to create a complete copy of your entire mailbox
- If you even forgot to back up your data for a month, and your hard drive fails, all of your emails and calendar entries will be permanently lost for that period.
- You need to remember to run the process yourself, involving 7-10 clicks
- If any emails are deleted after export, the deleted items are removed in the new backup as well.
Method 2: Backup Outlook OST File
OST files cannot be backed up directly. Attempting to simply copy an OST file is useless because the copied file cannot be opened on another PC or restored; Outlook will instead just create a new one from the server the next time it connects to restore Outlook backup.
Therefore, the correct method for backing up OST data is to export it to a PST file or use the Auto-archiving.
Use Outlook’s Built-in AutoArchive
If enabled, some data is auto-backed up:
- Go to File > Options
- Select Advanced
- Click AutoArchive
- Configure schedule & folder location for backup.
Method 3: Backup Outlook Emails 365 Using Drag and Drop
One of the simplest ways for Outlook 365 backup is by using the drag-and-drop method.
Just open the folder in Outlook, choose the emails you want to save, and drag them into a folder on your computer. This instantly creates a local backup of those messages.
- Open Microsoft Outlook.
- Go to the email folder you want to back up.
- Select the emails you wish to save. To choose multiple emails, hold Ctrl (Windows) or Command (Mac) while clicking.
- Drag the selected emails into any folder on your computer to create a backup.
How To Back Up Outlook to an External Hard Drive or Cloud?
External drives/USBs:
Backing up your Outlook data (.ost, .pst, or .olm) files to a flash drive or external hard drive is an easy way to keep an offline, portable copy of all your Outlook items.
This is especially helpful when moving Outlook to a new computer or protecting your data from unexpected problems.
The process is identical whether you’re using a USB drive, flash drive, or external hard disk.
Cloud Storage:
Instead of saving to Documents > Outlook Files, you can change the save location to your cloud folder.
ALSO: This is only recommended when your PST file is under 5GB to 10GB.
- Close Outlook
- Move your .pst file to your cloud folder
Examples:- C:\Users\<name>\OneDrive\OutlookBackup\
- C:\Users\<name>\Dropbox\Outlook\
- Open Outlook > It will prompt to locate the PST
- Browse to the folder inside the cloud storage
- Confirm and restart Outlook
How to Back Up Outlook? (Automatically)
When relying on Outlook for all your work and personal data, automatic and incremental backups are highly recommended for maximum data protection. Here are a few options for scheduling daily or weekly PST backups
Professional Outlook Backup Tools
Professional tools offer advanced features like scheduling daily or weekly PST backups, keeping multiple backup versions, performing incremental backups, and enabling one-click restoration.
Additionally, easy mobility of the Outlook profile from older to higher Outlook versions and vice versa, and hassle-free Migration of Outlook Profiles to a new computer.
- On your PC, download and install Remo Outlook Backup and Migrate Software.
- Open the tool and select backup.
- Select Smart Backup or Advanced Backup on the next screen.
- To begin the backup process with Smart Backup, simply click Next. Select the folders you wish to back up in Advanced Backup and then click Next
- Click View Report to see a list of the files that have been backed up, then Finish to dismiss the.
Enable Windows File History (System-Level Backup)
You can leverage the built-in Windows File History feature to automatically protect your PST file.
- Connect an external hard drive or USB drive to your computer.
- Open Settings > Update & Security > Backup.
- Click Add a drive and select the connected external drive.
- Turn on File History.
- Click More options.
- Scroll down to Backup these folders and click Add a folder.
- Select the folder where your PST file is stored (usually in Documents > Outlook Files).
- Windows will now automatically back up your PST file at regular intervals.
Sync PST With Cloud Storage (Conditional Use)
PST files can be synced using services like OneDrive, Google Drive, or Dropbox, but only under specific rules to prevent corruption.
This method works well ONLY IF Outlook is closed during the sync process, the PST file is not massive, and the sync provider is reliable.
This method does NOT work for OST files. Syncing OST files will corrupt them. For OST data, you must first export to a PST file.
- Close Microsoft Outlook completely.
- Move your PST file into your cloud storage folder (OneDrive, Google Drive, Dropbox, etc.)
- Wait for the sync to finish.
- Reopen Outlook, and Outlook will now use the PST from the synced location.
- Allow your cloud storage service to continue syncing updates whenever Outlook is closed.
Frequently Asked Questions?
Open Outlook > go to Tools > Export, then choose items and save the exported .olm file to a local or external location. You can also upload the OLM file to cloud storage for extra safety.
Outlook Web doesn’t support direct export, so sign in using the Outlook desktop app and export to a PST file, or download emails individually as .eml files. Alternatively, request a full data export via Microsoft Privacy Dashboard.
New Outlook currently doesn’t support PST/OLM export, so switch to Classic Outlook to export, or configure the account in another email client to back it up. Third-party email backup tools are also an option.
