How to Open a MBOX File online in Windows and MAC with a free .MBOX opener

Do you know the process of how to open mbox files? The term ‘mbox’ represents ‘Mailbox.’ It is a mail format created for storing and organizing in a single text file the email messages. 


Who uses mbox files?

The mailbox programs are saved as mbox extension in an email storage format on your computer. However, not all the mailbox programs make use of the mbox format. Only a few such as:

  • Apple Mail
  • Mozilla Thunderbird
  • Microsoft Entourage 2008,
  • Qualcomm Eudora

These programs use this mailbox program, and they only can open it.

You can view these with many text editors such as:

  • Notepad,
  • Open Office Writer
  • Microsoft Word. 



How to open mbox files


In Windows

  • Right-click on the file.
  • Click on open with and select the option ‘Choose Default Program.’
  • Select one of the options offered by Windows, as they are default programs available on your computer and it opens the file.
  • Click on Browse only in case Windows fail to show default programs. 
  • Search for a text editor or a mailbox software and click on ‘Open.’
  • Finally, click on ‘OK,’ .


Now you can download your Gmail data easily as Google offers MBOX. With this, you can do lots. You can keep a backup offline or move your emails into a new Gmail account or email service. 

Getting an offline copy previously of your Gmail means you need to download the Gmail archive entirely in Thunderbird over IMAP. The best part is now in a few clicks, and you are good to take on the Google Takeout website. 



There is a need to import into Apple Mail the MBOX file following these steps:

  • Copy to your Mac. the .mbox file…
  • Open Apple Mail.
  • Type “File->Import Mailboxes” menu command.
  • Check the option ‘Files in mbox format’ and click ‘Continue.’ 
  • IN the next window, select MBOX and click on ‘Continue.’
  • Done


An MBOX file has mail storage saved in one text file. The primary name given in Apple Mail to this inbox mail folder is INBOX.mbox and Mac OS X is the default email program. 


How to import into Thunderbird your Gmail MBOX

Recently, more data is stored in the cloud. The contacts, email, photos, documents, calendar entries, and a lot more are on the Google servers.  Thus, it is best to import into Thunderbird your Gmail Box.

  • Use Mozilla Thunderbird as it is open-source, free, runs on Mac, Windows, and Linus, while it natively supports MBOX format.
  • Install Thunderbird on the computer, add any email account to Thunderbird after opening it.
  • Close the email account after adding to Thunderbird and locate the 

C:\users\NAME\AppData\Roaming\Thunderbird\Profiles\########.default\Mail\Local Folders\ folder on your computer, where your username is your NAME and ######## is eight random characters.



The mbox extension is the common format to store on a hard drive your email messages. All the messages are stored as a long, single, text file in a string of e-mail concatenated messages. MBOX were used on Unix.

This format also includes non-text attachments such as files and images.