There are several reasons why you might want to export your mailbox in Outlook:

• Backup Emails: Create a secure copy of your emails to prevent data loss.
• Switch to a New Device: Easily transfer your mailbox when moving to another computer.
• Transfer to Another Account: Move emails to a different email account or service.

Follow the steps below to export your emails in Outlook:

1. Go to the File menu in Outlook, and select Open & Export > Import/Export.

2. In the Import and Export Wizard, select Export to a file and click Next.

3. Choose Outlook Data File (.pst) as the file type and click Next.

4. Select the mailbox folder you want to export (e.g., Inbox, Sent Items, or the entire mailbox).
Check the box for Include subfolders to ensure all nested folders are included. Click Next.
Note: You can only export items from one email account at a time.

5. Click Browse to choose where to save the exported file on your computer. Enter a file name and click OK to proceed.

6. Click Finish to begin the export process.
If prompted, you can set an optional password for the exported file to enhance security.

Reference: Export emails, contacts, and calendar items to Outlook