The files in a Google Takeout that contain the emails from a past account are in the .mbox format, otherwise known as MBOX files. But how do you open them? This article outlines some of the easiest ways.
Third-party email platforms are generally the easiest way to open MBOX files. The platforms listed below are more common and widely-used, though there are likely others that will work as well. Please note that none of these are directly supported by UMaine IT; if you encounter any issues, you may want to speak with their support team.