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The Ultimate Guide to Split MBOX Files by Size for Easy Management

Published On March 11th, 2024 • 4 Min Read

Note: Get step-by-step instructions here to split MBOX files by size in a few simple steps.

Is your email archive becoming unmanageable, causing your inbox to overflow?

MBOX files, usually used to accumulate your email messages, can grow to unwieldy sizes over time, making them quite difficult to work with.

In this blog post, we will explore the process of splitting MBOX files by size, allowing you to take full control of your email archive and streamline your digital workspace.

Understand What MBOX Files Are?

Before we delve into the process of splitting, let us briefly try to grasp the concept of what MBOX files are.

An MBOX file is a plain text file which helps in storing your email messages in a sequential order.

It consists of numerous email messages that are linked together, with each message differentiated by special marks or symbols, called delimiter.

Why Split MBOX Files by Size?

If we try splitting MBOX files by size, we get to take advantage of the benefits that it tends to offer.

It helps prevent MBOX files from becoming too large, which can lead to performance issues in email clients and backup processes.

Adding on, splitting by size allows for easier management and organization of email messages, making it simpler to locate specific messages within your archive.

Now, the question is how to split MBOX file by size? Is there a good and safe method?

The answer is yes. You can accomplish this task in just a few clicks using Online MBOX Splitter.

Let us all figure out its further benefits which it serves to the different user segments by reading the below use cases.

Cases Where You Can Use It to Split Large MBOX Files

  • For Businesses with Extensive Communication: This feature allows them to break down MBOX files into smaller, more manageable sizes, aiding in efficient storage and backup processes.
  • For Digital Nomads: They benefit from the ability to split MBOX files on-the-go, ensuring their email data remains organized regardless of the location.
  • For Students and Researchers: Managing substantial email correspondence can use the size-based splitting to categorize and access relevant information swiftly.
  • For Personal Users: This feature simplifies inbox organization, preventing overload and making it easier to locate essential emails.

Also Read

How to Split MBOX Files by Year?

Step-by-Step Procedure

Now, let us walk through the step-by-step process of splitting MBOX files by size:

  • Unlock the MBOX File: Make use of an Online MBOX viewer to unlock the MBOX file you want to split. This will permit you to have access to the inner contents of the file and its complete size.
  • Send Your MBOX File: So, as per your software, there may be an option available to send your email’s MBOX file into individual files.
  • Now, Access Text Editor: Now, if your software is not supporting the feature of exporting, you can still split MBOX files making use of a text editor. Simply, unlock the MBOX document in a text editor that stands capable of handling huge files.
  • Recognize Size Limitations: Navigate through the file and recognize the size at which you wish to divide MBOX files into separate files. This could be totally contingent on a certain file size limitation or a manageable size for an easy way of handling.
  • Break Down the File: Also, you can manually split MBOX files into multiple files based on the size factor. Save each split portion as a new MBOX file with a descriptive filename that depicts its size (e.g., ‘inbox_1024MB.mbox’).
  • Make Validation of Your Split: Now, once you have divided the MBOX file, validate that each new file comprises the messages within the particular size limit.
  • Now, Create Backup: After using MBOX file size splitter tool for the files, make a consideration for backing up your email archive to abstain any data getting lost. Also, arrange the separate MBOX files in a folder structure that makes them easier to gain access.


MBOX File Size Splitter is an essential tool for individuals and businesses dealing with large email archives. Now, by following this procedural step-by-step guide, you can better manage and organize your email archives.

So, whether you are dealing with a large emails or simply looking to streamline your digital workspace, splitting MBOX files by size is an immensely valuable technique. Also, MBOX File Size Splitter is the solution for anyone who is seeking a streamlined approach to manage, store, and access their email data effectively.

So, it is always better to take charge of your email archive and enjoy a more efficient email management process.