Home » Blog » How To » How to Split Large MBOX Files with MBOX Splitter Tool?

How to Split Large MBOX Files with MBOX Splitter Tool?

Published By Jamie Kaler 
Rollins Duke
Approved By Rollins Duke
Published On May 1st, 2024
Reading Time 7 Min Read

Overview: Do you have a large size of MBOX files and do you want to split MBOX file into smaller files? If so, then read this article. Here you will get a simple and easy-to-use solution to divide the MBOX file into small parts. Read more to know more.

The oversized MBOX files and their consequences seriously affect millions of users. The large-sized MBOX files lead to various issues and cause especially programming crashes, lapsing huge timing on loading mailbox items, hardware failure issues while sharing such large files, etc.

MBOX files are obtained from a large number of email clients and services. Some of them are Apple Mail, Webmail, PocoMail, Gmail, Postbox, Entourage, Eudora, Opera, Netscape, Thunderbird, Spicebird, Evolution, Power Mail, Claws Mail, SeaMonkey, Sylpheed, GyazMail, Gnu, Mulberry, Sparrow, The Bat! etc. Some use the original version of the MBOX file while others use an extended or modified edition of the mailbox file.

This article describes three manual & free ways to split MBOX file into smaller files or individual files. There is also an expert’s recommended MBOX Splitter Wizard, which enables the users to divide MBOX files into smaller files based on Date, Size, or From the User fields. It also allows splitting MBOX files for the emails between two dates.

My mail list has been hoarded with MBOX File and the Thunderbird mailbox size limit exceeded about 5 GB. Due to the large size of the MBOX file, I was unable to open my mailbox items in Thunderbird and any of the other Email Clients. I decided to finally split MBOX file into smaller files so that I could share them with my client easily. All references are acknowledged. I appreciate any help you can provide. – Eric Neyas, Texas

Oversized MBOX File – Common Failure Issues

In MBOX Files, all the email content and related information are saved in a single text file. All the emails and messages are saved in serial one after another. Each message is separated with the ‘From’ keyword while it terminates with a blank line.

An email conversation is a continuous process. A user may receive several emails regularly. Hence the size of the mailbox file attached to it is also increasing. It results in various causes of working with MBOX files like an error in opening MBOX files, incompatibility with the platform, etc.

The major issue that is faced by the users is the corruption of MBOX files. Large MBOX files are also seen to be causing abnormal behavior in some mail clients. As though, there is no file size limitation imposed by new Thunderbird editions for saving emails on MBOX file in the present time. But, older Thunderbird versions support MBOX files only up to 4 GB.

Best and Advanced Expert MBOX Splitter Tool for Mac & Windows

Both methods discussed above are completely free and require just some manual tricks to split MBOX file into smaller files. But, to accomplish it, a user must take care of the fidelity of the emails. It may harm the internal folder structure and integrity of the emails. Finding only the required messages from a large number of mailbox items and performing operations upon them one by one is not so quite easy.

Hence, to split MBOX file into smaller files we need an advanced and professional RecoveryTools MBOX Splitter Tool. In this scenario, there comes the MBOX Splitter Wizard that allows a user to split MBOX by Date, into individual messages by User ID (from), or based on size. It allows splitting all types of MBOX files including Thunderbird, Google Takeout, etc.

Download this amazing MBOX Splitter Tool from Given below link:

Note: The software will allow splitting only the first 25 emails to a new file during the trial version. The working of the utility is very simple. It also displays the preview of the emails in its working panel. One can analyze its working with the help of its working screenshot.

Quick Steps to Split MBOX File into Smaller Files

  • Step 1: Download & run the MBOX splitter tool.
  • Step 2: Click on the Open button to load files.
  • Step 3: Choose between Select Files or Folders option.
  • Step 4: All the folders and subfolders will appear.
  • Step 5: Click on Save icon and apply splitting filters.
  • Step 6: Browse the location to save resultant data.
  • Step 7: Finally, click on the OK button to split MBOX file into smaller files.

Why Professional Software Over Manual Methods?

  • This MBOX splitter tool provides dual options to upload your single and multiple MBOX files and folders to the panel as per requirements.
  • Also, it supports all types of MBOX files exported from any email client including Thunderbird, Google Takeout, Opera Mail, SeaMonkey, Horde Mail, Apple Mail, etc.
  • This MBOX splitter tool maintains all the folder hierarchy and email components including Bcc, Cc, To, From, Subject, Date, Formatting, Font Size & Colour, sender and receiver information, etc.
  • Users can use the advanced search option with multiple filters to find any particular and required email, which you want to analyze, and to split MBOX file into smaller files.
  • After uploading your complete data, users can analyze all the folders and subfolders on the panel including email body and header details.
  • This software is compatible with all Mac & Windows versions including Windows 11, 10, 8, 7 and older versions and MacOS 11 (Big Sur), MacOS 12 (Monterey) & MacOS 13 (Ventura), 10.15(Catalina), 10.14(Mojave), 10.13(High Sierra), 10.12(Sierra), OS X 10.11 El(Capitan), 10.10(Yosemite), 10.9 (Mavericks), and 10.8(Mountain Lion).

Complete Working Steps to Split MBOX into Separate Files

  1. Download and install the MBOX splitter tool on your system using the download buttons.

    MBOX splitter tool

  2. Click on the Open button and choose between the Select Files and the Select Folders button to upload your single and multiple data.

    upload your single and multiple data

  3. After uploading your complete data, all the folders and subfolders will appear on the screen, so that users can analyze their data without wasting their time.

    uploading your complete data

  4. One can easily change or choose splitter options according to your requirements.

    splitter options

  5. Start the process by clicking on the Next button.

    Start the Split large MBOX into Separate Files

Major Advantages of Splitting MBOX Files Are:

  • Share only the required emails with your seniors or colleagues instead of the whole mailbox.
  • As large MBOX files give more chances to corrupt, hence splitting it ensures the data security.
  • Corresponding email client hangs for a long time and consumes more time. Hence, loading only a few mailbox items will certainly reduce time in loading mailbox items.

Frequently Asked Questions

  • Ques 1: How can I open MBOX files for free?

    Ans: Yes, you can open MBOX files for free using the RecoveryTools MBOX Viewer tool.

  • Ques 2: What is MBOX storage?

    Ans: MBOX is a file format to store an email detail including the email header and body details of a folder. It is used by multiple email clients like Thunderbird, Apple Mail, Opera Mail, SeaMonkey, etc.

  • Ques 3: I have 1000+ MBX files, which I want to split to save my storage space. Does this software support MBX files?

    Ans: Yes, our MBOX splitter tool supports all types of MBOX versions including MBX, MBS, etc.

  • Ques 4: I want to convert the MBOX file into an Outlook data file, is this tool saved in it?

    Ans: For MBOX to PST conversion, you should use one of the best and most advanced MBOX converter tools for Mac & Windows.

The Verge

A large number of email clients are responsible for creating MBOX files. With time, the emails are continuously received and sent by the user hence increasing the size of the MBOX file rapidly. But as it led to various issues, then most of the users decided to split MBOX file into smaller files.

This article successfully describes the whole scenario of oversized MBOX files and how to manage them. It solves various queries of the users like ‘how can I split large MBOX files, how to break MBOX files into smaller parts, how can I split MBOX by date’, etc using the MBOX splitter tool.