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Open MBOX File: A Step-by-Step Guide

Justin Cener ~ Modified: March 12th, 2024 ~ How to ~ 6 Minutes Reading

Are you trying to open MBOX but are unable to? Not an issue, We solve all the queries of our users. We will help you through our step-by-step guide to teach you how to open MBOX file whether it is Chrome, Windows, or MacOS. Just be with the article till the end and find all your answers.

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MBOX files store all the email data including several email messages and all of their associated attachments. Numerous email clients, including Google Takeout, Mozilla Thunderbird, Spicebird, Eudora Mail, and many more help to Open MBOX Files.

MBOX File Format Variations

There are four types of MBOX File Formats. Take a look at the following:

  • MBOXO: These supports are supported by Eudora where the messages are stored as attachments. This fomat is not a standard MBOX format. Moreover, its meaning or usage depends on the context it is being used in, however, it may be related to archiving sent messages.
  • MBOXRD: These are supported by Qmail, Thunderbird, and Netscape which begins the messages with “from”. This file format is associated with MBOX and is a valid format as well.
  • MBOXCL: Here headers are used to locate the starting message and emails are transformed before appending. It is not a standard MBOX format and may even be specific to a particular email client.
  • MBOXCL2: Just like MBOXCL it also uses content length (header) to indicate starting messages. However, it does not transform email before storing. This is also not a standard MBOX format and is specific to particular email client application.

Default Location of MBOX Files for Different Operating Systems

Here are the default locations of MBOX files in Thunderbird, Apple Mail, and Postbox for both macOS and Windows that will easily help you to Open MBOX File:

Mozilla Thunderbird

  • Windows Location: C:\Users\\AppData\Roaming\Thunderbird\Profiles\\Mail
  • MacOS Location: ~/Library/Thunderbird/Profiles//Mail

Apple Mail

  • MacOS Location: ~/Library/Mail/V8
Note: “V8” may be replaced with a different number depending on the version of Apple Mail.


  • Windows Location: C:\Users\\AppData\Roaming\PostboxApp\Profiles\\Mail
  • MacOS Location: ~/Library/Application Support/PostboxApp/Profiles//Mail

How to Open .mbox Files?

MBOX Files are plain text files that can be opened using standard MS applications such as Thunderbird and Apple Mail. Furthermore, both MacOS and Windows operating systems offer applications, where MBOX files can be viewed. However, there is one more option to open .mbox file, which is using Chrome browser. In the upcoming paragraph, you will find steps on How to Open MBOX file in Windows including Mozilla Thunderbird, Apple Mail, Postbox, and Chrome, macOS.

How to Open MBOX File in Chrome?

To open an MBOX File in Chrome, first, you need to find out if Chrome supports MBOX files. So the answer is no, Chrome browser supports HTML file format! In order to open MBOX file in Chrome browser, you need to convert MBOX file format into HTML first. If you have already done so, then follow the steps given below:

  • Once you’ve converted the MBOX file to HTML, save the HTML file to your computer.
  • Launch the Google Chrome web browser on your computer.
  • To view the HTML file in Chrome, simply drag and drop the HTML file onto an open Chrome tab or window.
  • Alternatively, you can right-click on the HTML file and select “Open with” and then choose Google Chrome.
  • Chrome will open the HTML file, displaying its content, including any text and images, just like a web page.

By following these steps, you can easily open .mbox file in Chrome after converting it to HTML format.

Opening MBOX File/Folder in PostBox

Follow the given steps to open MBOX files in PostBox:

  • First and foremost, open PostBox.
  • Now go to the File menu option and click the Import Button.
  • Just after clicking the import option, you will be able to choose the MBOX folder from your computer.
  • After selecting the MBOX folder, click Import.

How to Open MBOX file in Windows?

To open MBOX Files in Windows, you need to take the help of any Microsoft application like Mozilla Thunderbird, Outlook, etc.

  • Just install any of the applications you want.
  • Afterward, go to File or Open tabs.
  • Choose the .mbox file to open.

Step-by-Step Guide Open .mbox Files in Apple Mail

To open an MBOX file in Apple Mail on macOS, follow these steps:

  • First and foremost, make sure you have Apple Mail installed on your macOS. It is the default email client on Mac.
  • Then, find and locate the MBOX file you want to open. It should be saved somewhere on your computer, or you might have received it via email.
  • Import MBOX File:
    • Open Apple Mail on your system.
    • In the Apple Mail menu at the top-left corner of the screen, click on “File”.
  • In the “File” menu, select “Import Mailboxes”. Once you do that, a dialog box will appear.
  • In the dialog box, choose “Files in MBOX format” and click the “Continue” button.
  • Use the file browser to navigate to the location of the MBOX file you want to open. Select the MBOX file and click the “Choose” button.
  • Apple Mail will ask you to choose where you want to import the mailbox. You can select an existing mailbox or create a new one. Once you’ve made your selection, click the “Continue” button.
  • Upon doing so, Apple Mail will begin importing the MBOX file. The time it takes will depend on the size of the file.
  • Once the import is complete, you can access and view the emails from the imported MBOX file within Apple Mail. You will find them in the mailbox you selected during the import process.

Which is the Best Way to Open MBOX Files Instantly?

You can use the verified Corbett MBOX Viewer to instantly open the bulk of MBOX files without facing any trouble. If you use the software, you would not need to install any other application as it does it all. Along with that you can also change its file formats and apply filters to the folder as per your needs. All you need to do is just install the application, then upload your MBOX file, and open it whenever you want.

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We have provided a bunch of information on how to open MBOX files including Windows, Chrome, and MacOs. We have also covered some of the major information related to MBOX file format that users need to know. Hope this ultimate guide might have helped you, thanks for reading!

Read More: Import MBOX to Outlook

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