Can I open MSG files without Outlook?

Yes, you can open MSG file on Mac without Outlook by installing an MSG Viewer for Outlook app from the app store. Follow the following instructions.
1. Install the MSG Viewer for Outlook app from the App Store. Use the Launchpad to open the app when it has been installed.

2. Next, under the Opening Files section, you can choose which client or address book program to start.

3. Choose Quick View to view the file instantly, or choose one of the conversion options (such as Convert to PDF) to change the file’s format. After adjusting the parameters, choose File > Open from the menu bar.

4. Locate and pick your MSG file in the Finder window, then click the Open button. This will start the process of converting MSG files to the freely available EML format.