Are you wondering how to open large MBOX files? If your answer is yes, this blog will guide you step by step. Here, you will learn about the different methods for smoothly opening large MBOX files in Chrome, Apple Mail, Windows, or macOS.
TABLE OF CONTENTS
What is an MBOX File and Its Default Location?
MBOX is a popular file format introduced in 1975 as part of UNIX 6th Edition. It is also known as “concatenated, ” meaning that the information in an MBOX file is linked as a long chain of text strings. An MBOX email message begins with a header. There are four types of MBOX files like .mboxcl2, .mboxrd, .mboxcl, and .mboxo.
Some key characteristics of MBOX files are:
- Plain text format: MBOX files are simple text files that can be opened and viewed using any text editor. All emails in an MBOX file are represented in plain text, making them easy to read.
- Message delimiter: Email messages in an MBOX file are separated by a special delimiter, usually consisting of a “From” string at the beginning of a new message line. This string indicates the beginning of a new email.
- Cross-platform compatibility: Since MBOX files are plain text and in a standardized format, they can be easily transferred between different operating systems and email clients without compatibility issues.
Supported Email Clients and Default Location of MBOX File
MBOX file is supported by several email clients, including Apple Mail, Thunderbird, Eudora, Postbox, Google Takeout, Claws Mail, Opera Mail, etc. Here is the default location of the MBOX file in multiple email clients.
- Apple Mail: .. /User/Library/Mail/Mailboxes/
- Thunderbird for Windows: C:\Users\[username]\AppData\Roaming\Thunderbird\Profiles
- Thunderbird for Mac OS: ~/Library/Thunderbird/Profiles//Mail
- Eudora: ..\[Your user name]\Application Data\Qualcomm\Eudora
- Postbox for Windows: C:\Users\\AppData\Roaming\PostboxApp\Profiles\\Mail
- Postbox Mac OS: ~/Library/Application Support/PostboxApp/Profiles//Mail
How to Open Large MBOX Files Manually Using Email Clients?
As we mentioned earlier MBOX file is supported by Thunderbird, Apple Mail, and many other email applications. We are going to read MBOX files using some supported email apps.
1. Read MBOX Files in Chrome
For opening large MBOX files in Chrome, you must first convert MBOX to HTML file format supported by Google Chrome. To perform this conversion, you can use converter tools for quick results. After conversion, follow the steps mentioned below:
- Firstly, launch the Google Chrome web browser on your computer.
- Then drag and drop the file into an open Chrome tab or window.
- Alternatively, you can right-click the HTML file >> Open with >> Google Chrome.
2. Open Large MBOX Files in Apple Mail
- Open Apple Mail on your PC.
- Select File > Import Mailboxes.
- Select your MBOX file.
- Click Continue.
- Navigate to the location of your MBOX file and select it.
- Click Choose to import your MBOX file.
- Apple Mail will confirm the location of the imported MBOX file.
- Finally, click Done.
3. Open MBOX Files in Windows Using Thunderbird
- Open the Thunderbird desktop application on your system.
- Sign in to your account and go to the “File” tab.
- Click on the “Open” button and select “Saved Messages”.
- Select the MBOX file you want to open from your system.
- Finally, click on the “Open” button.
How to Read MBOX Files Without Email Clients?
It is difficult to open large MBOX files without installing any email client. However, using Yota MBOX Viewer tool, you can view MBOX file without any applications. It supports MBOX files exported or created by any email client. The tool also does not have any size issues, so you can open MBOX files without losing a single piece of information.
With this tool, you can convert MBOX to PDF file, MBOX to PST, and many other file formats, along with attachments. Also, it helps you directly import MBOX to Gmail and many other email accounts. It is known for its accurate results and maintains the hierarchy of folders throughout the procedure. Moreover, it is successfully operable on any version of Windows OS, including Windows 11.
Steps to Open Large MBOX Files Quickly
- Download and install the software on your PC.
- Click Open > Email File Formats > select MBOX file.

- Read MBOX file in 4 preview modes with all details.

- Click Export and choose the required format.

- Lastly, click on the Save button.

That’s it!
Final Thoughts
Here we have discussed everything about MBOX files, supported email clients, and how to open large MBOX files in Windows, Chrome, Apple Mail, and Thunderbird. If you don’t have any email application installed on your computer, we also recommend the free email viewer, which is safe and secure.


