Use an email client that supports MBOX files, such as Thunderbird, Apple Mail, or eM Client
Install and open the email client
Import the MBOX file using the client’s import or local folders option
If needed, install an MBOX import add-on or extension
Select the MBOX file from your computer
Wait for the emails to load into the mail client
Open the imported mailbox and browse the messages
Use an MBOX viewer tool if you only need to read the file without importing it
Convert the MBOX file to another format if your email client does not support direct opening