To back up Microsoft Outlook Emails, utilize the built-in export feature:
Open Microsoft Outlook and access the "File" menu.
Select "Open & Export" and choose "Import/Export."
In the Import and Export Wizard, opt for "Export to a file" and proceed.
Choose the file type "Outlook Data File (.pst)" and select the desired mailbox or folders for backup.
Specify the backup location and file name for the exported PST file, and complete the export process by clicking "Finish."