Files with the extension MSG are simply Outlook mail messages. These files can be opened with Outlook or with a couple of products available online. You may see this file extension when an email is attached to another message. If you do not have Outlook on your computer, try using "BitDaddys EmailOpenViewPro" or "Encryptomatic MsgViewer Pro" applications.
Launch your Outlook application.
Click "File" in the main menu bar or click the Office icon button in the top-left corner of the interface. Scroll down and click "Open."
Find the MSG file that you want to view. Highlight it and click the "Open" button.