Use classic Outlook on a computer to export all Outlook.com/Hotmail mail (including folders and subfolders) to a .pst backup file, then clean up storage in Outlook.com.
1. Install or use classic Outlook (desktop)
A desktop Outlook app (classic Outlook) is required to export to .pst. The export feature is not available directly in Outlook.com web.
If classic Outlook is already installed, sign in with the Hotmail account in Outlook and let it fully sync all folders and subfolders.
Note: Importing/exporting via .pst is not supported in the new Outlook for Windows; use classic Outlook instead.
2. Prepare the mailbox for full export
Before exporting, ensure Outlook has downloaded all mail:
- In classic Outlook, select the Hotmail account.
- Go to Account settings > Account Name and Sync Settings.
- Move the Download email slider to All so all messages (not just the last year) are available locally.
- Allow time for Outlook to finish syncing.
Also avoid exporting directly to a OneDrive-synced folder, because OneDrive can block automatic syncing for .pst files.
3. Export all mail to a .pst file
- In classic Outlook, select File > Open & Export > Import/Export.
- Select Export to a file, then Next.
- Select Outlook Data File (.pst), then Next.
- Select the top-level mail folder for the Hotmail account and ensure Include subfolders is checked so all folders and subfolders are included.
- Select Next.
- Choose a location on the PC (not in OneDrive) and a file name for the backup .pst, then select Finish.
- Optionally set a password for the .pst and select OK.
This creates a full backup of emails, folders, and subfolders that can later be opened or imported in Outlook.
4. Verify the backup
To confirm the backup works:
- In classic Outlook, go to File > Open & Export > Open Outlook Data File.
- Browse to the .pst file created and open it.
- Confirm that folders, subfolders, and messages appear in the added data file.
5. Free up space in Outlook.com
After confirming the backup, reduce Outlook.com storage:
- Sign in to Outlook.com.
- Go to Settings > Account > Storage.
- Under Email storage, review how much space each folder uses and use the options to permanently delete items (or those older than 3, 6, or 12 months).
- Review large emails and attachments by sorting folders by size and deleting unneeded messages.
- Empty Junk Email and Deleted Items folders.
- For further space, delete emails with large attachments; deleting the message removes the attachment from cloud storage.
Repeat until the storage usage is within the desired limit.
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