Sure, you can. Outlook does not need to be installed in order for the DataVare MSG to MBOX Converter to function. For users without Outlook installed on their system and with only MSG files, this makes it incredibly convenient.
Using this instrument, you can:

Directly convert MSG files to MBOX format for use with SeaMonkey/ Apple Mail/ Thunderbird/ and other programs.
Convert an infinite number of MSG emails in bulk at once.
Preserve the original email properties, attachments, and folder structure.
If you do not want to convert everything, choose particular folders.
Check emails using the integrated preview feature prior to conversion.
Function flawlessly on all major Windows OS versions, including Windows 11/ 10/ 8/ 7/ XP/ and others.
Very UI interface no technical expertise is needed.

Therefore, this software is an independent option for accessing MSG emails in email clients that support MBOX, even in the absence of Outlook. This tool comes with a free demo so users can read more about it.