How do I convert RPMSG to PDF without Outlook?

I had the same issue when I received a few protected Outlook emails in RPMSG format. Most manual methods require Outlook and can only convert one email at a time.

I ended up using Advik MSG to PDF Converter to convert RPMSG to PDF files, which supports both RPMSG and MSG files. I simply added the files, selected PDF as the output format, and started the conversion. It preserved the email formatting, attachments, and headers, and I didn't have to install or use Outlook. If you have multiple RPMSG files, the batch conversion feature is a big time saver.