This method will help you backup your outlook 2003 email.
Quick Access Control Panel Menu and Utility by Command Line Part1
- At Menu Tools > Option and go to Mail Setup tab
- Left Click “Data Files”
- Select “Personals Folders” and click “Open Folder…” now you will see New Window Explorer
- Close your Outlook and Copy all files in Folder
- Paste into your Backup Folder (ex. d:\backup_outlook)
End Backup Process
 Import Outlook Mail from Backup file.
- Open Outlook Application.
- Create your Email Account (same Account that you backup)
- go to Menu Files > Import and Export
- Select Import from another or file and then click Next
- Select “Personal Folder file(.pst) and click Next
- Test or Verify your Data first and Delete your backup files
Backup Outlook 2003 mail