Using a trustworthy program is the simplest approach to convert message emails to PST if Outlook is unavailable. Because an MSG file cannot be directly converted manually without Outlook.
In that case, my suggestion is to use a utility like Softaken MSG to PST Converter. It is very helpful for converting large files without losing any emails or changing formatting. I also use this tool for managing multiple msg files in PST format, but I do not have Outlook installed, so this software helped me make the task easier.
