Learn to Split Outlook PST File Into Smaller Parts Easily

Aldrich Calvin | Modified: December 16, 2022 | General | 6 Minutes Reading

Overview: Here, we will discuss the reasons why users should split Outlook PST file into smaller parts and the best methods to complete this task without losing any critical data.

If you have been using Microsoft Outlook for a long time, then there is a possibility that the size of your Outlook PST file would be large. If the size of the PST file has increased too much, then you may encounter performance issues while working with Microsoft Outlook. The Outlook application starts working abnormally, and there can be chances of a sudden shutdown of the email application or you may find it in lagging. Moreover, PST files are prone to corruption and any damage to those files can cause the loss of entire mailbox data. 

This is why it is advised to keep the mailbox data stored in multiple PST files. To achieve this, the user needs to know how to split large PST file into smaller parts. This will decrease the chances of losing all of the mailbox data and minimize the damage in case a PST file gets corrupted due to any reason. So, to split oversized PST files, follow this article and know how to split Outlook data files using the best tips and tricks.

What is PST File?

Basically, a PST file i.e. Personal Storage Table is a central repository of Outlook elements which includes emails, calendars, contacts, tasks, notes, journals, etc. There are two types of PST files i.e. ANSI and Unicode files. The ANSI PST file has a predefined storage limit of 2 GB and it is supported by Outlook 2002 and earlier versions of it. On the other side, Unicode PST file has remarkably increased storage capacity and it is supported by Outlook 2003 and later versions of it.

After knowing about Outlook files, let us now discuss the methods to divide large-sized PST files.

How to Split Large PST File Into Smaller Parts Manually?

Archive Oversized PST File

Archiving older Outlook PST files not only helps to reduce the size of a mailbox but also divides PST files into smaller segments. The steps to archive the Outlook mailbox are mentioned in the following section:

  1. Open Microsoft Outlook.
  2. Choose the PST file which you need to split.
  3. Click on the File tab and select Info.
  4. Now, Select Cleanup Tools.
  5. Choose Archive from the available options.
  6. After that, a dialog box will appear. Select the “Archive this folder and all subfolders” option.
  7. Now choose a folder from the list.
  8. Next, the option Archive items older than will appear. Choose proper dates from the calendar to split the Outlook PST files into smaller parts.
  9. Click Browse to select the destination location of the new file.
    Note: The default name of the resultant file is Archive PST. After providing the storage location, Click the OK button.

Import and Export to Break Data

You can break PST file into smaller parts using the in-built Import and Export feature. So, to know how to split Outlook PST file into smaller parts, follow the steps mentioned below:

  1. Open Microsoft Outlook.
  2. Create a new Outlook file.
  3. Click on the File tab, choose More Items,
  4. A Create or Open Outlook Data File window will open. Provide the storage location for the resultant file.
  5. Click OK.
  6. You can now access the newly created Outlook PST file in the application window.
  7. Now, Click the File tab and then open and select Import to split Outlook PST file into smaller parts.
  8. A window will appear. Choose the Export to a file option from the list and click Next.
  9. Select Outlook Data File (.pst) and click Next.
  10. After that, select the folder that you need to export data from and select Next.
  11. Now, click the Browse button to choose the folder in which you want to export data.
  12. Open Outlook Data Files window will appear. Choose the file to which you want to export data and click OK.
  13. Now, choose a proper option from the given alternates and click on Finish.

How to Split Large PST Files Into Smaller Parts Effortlessly?

The manual methods discussed in the above section help the user in breaking the large-sized Outlook PST file into smaller parts. But these procedures may appear as a challenge for novice users. Another aspect of executing these steps is that these procedures are very time-consuming as well. So, to divide oversized PST files hassle-free, it is always suggested to use an automated solution such as SysTools Split PST Tool which is designed specially to break big PST files into smaller segments.

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Advantages of Using This Tool to Split Outlook PST Into Smaller Parts

This tool serves the user with various advantages over manual solutions. The additional functionalities offered by the tool prove to be useful in this task.

  • The tool can divide a PST file based on multiple parameters like size, Date, Year, Folder, Category, Email ID, etc.
  • A simple user interface ensures that the user has no difficulty in understanding and following the procedure to split Outlook PST file into smaller parts.
  • The user has the option to choose the desired size of the exported PST file between 1 MB and 1 TB.
  • This tool has support for both ANSI and UNICODE PST file formats.
  • The user can add files into the tool either one at a time or import an entire folder at once.

How to Split Large PST file into Smaller Parts? Step-by-Step Solution

The user is advised to use this easy-to-follow procedure to split the Outlook file into smaller segments.

  1. Install and open the Split PST tool.
  2. Use the Add File(s)/Add Folder button to import the data files into the software.
  3. Users can choose to split the PST file by Size, Date, Category, Year, or many more.
  4. Also, provide the desired split value for PST file segmentation.
  5. Next, check the summary of the provided information and click Next.
  6. The tool will start the process of exporting the PST file(s) as instructed by the user.


After reading this article, now users know how to split large PST file into smaller parts using multiple ways. Users can choose the desired solution which best suits their requirements. As manual methods have some limitations such as it is time-consuming as well as some technical expertise is required. Hence, there is a need for the above-mentioned professional application to make the entire process trouble-free.