How to reduce size of Outlook PST file to Improve Outlook performance

How to reduce size of Outlook PST file to Improve Outlook performance

While working with Outlook PST files, sometimes it is required to divide its contents for size management. This splitting technique prevents the data corruption due to its size limitation. The PST file can be split according to specific criteria to avoid the threshold limit of file size. Splitting operation can be performed via archiving or creating a new PST file. You can divide the PST file in four ways – by date, year, size or folder with the help of a program namely, Split PST, which is reviewed in the following segment. Each of the option is used in different scenarios. We will discuss the requirement to divide the PST file as well manual methods for splitting it into many files.

Situations When PST Splitting is Required:

  • I used to work with large sized PST file then I felt that the performance of MS Outlook is reduced and it became very difficult for me to stay dynamic with my continuous tasks due to its low data capacity. This could have led to PST file corruption. To prevent from this scenario, PST splitter is what I implemented to use.
  • A person within an organization needed to open a Unicode PST file into another machine due to the system failure and the new system has an older version of Outlook that is capable to make ANSI PST file up to 2 GB then the person had to split his Unicode PST file into smaller sized files up to 2 GB for smoother compatibility and operations.

Split PST Files Manually:

A person can split the PST files by following some manual methods. Various methods are:

1. Archiving the PST files – Archiving is an inbuilt feature of MS Outlook and can be performed by following the steps: 

  1. In Outlook application, open a PST file you need to move.
  2. Go to the File tab, and click on the Archive
  3. A dialogue box appears to you; now select the radio button besides “Archive this folder and all subfolders”.
  4. Select the specified folder you wish to archive. Note that you can select only a single folder at a time.
  5. The next option will let you to decide the items to be archived older than the specified date.
  6. Check the box if you wish to archive the emails under “Do not Auto Archive” option also.
  7. Now select the destination path by clicking on Browse tab and click

Now go through the destination folder to view the archived files.

2. Import / Export Option – This feature can be achieved by performing the following steps:

  1. Go to the File tab, and click on the Import and Export option, a wizard will appear to you.
  2. Click on Export to a File option and hit the Next
  3. Select Personal Folder File (.pst) and click Next
  4. Select the folder needs to export and mark the checkbox if you wish to include its subfolders also.
  5. If you wish to apply filters to export the limited data, click on the Filter tab and apply various filters of your choice.
  6. Click on the Next button and select the destination folder.
  7. Next option is to deal with duplicacy, select any one from the available option and click
  8. Now change the name of creating folder if you want and set a password if security is required for you.
  9. Check the box if you want to save the password in your password list and click OK

Now you can see the exported data by visiting to its destination path.

3. Moving to Another Folder – This option will move the contents of a folder into another folder to free the required space.

  1. Go to the File > New > Outlook Data File.
  2. Select the type of storage by clicking on Office Outlook Personal Folders File and click
  3. A window is opened on the screen, now provide a name for new PST file and select the destination path.
  4. Now go to the Edit menu and select Move To Folder
  5. Now select any of the available folders or create a new folder where you wish to move the items and click

Now you can check whether the items are moved or not by selecting the specifying folder.

Split PST Files Using Tool:

All the above methods are little convoluted and the process is so lengthy. The chances for mistakes are high and it is time taking process. In addition, it is not guaranteed that these methods will work with very large sized PST files successfully; there is a chance to lose the PST files data. If you wish to perform an optimum solution for oversized PST files, you can go through some third-party software to split your PST.

This review will be discussing about the working of a third-party utility to split your PST file accurately, namely Split PST.

Steps to Perform the Split of a Large sized PST File:

Step 1:- After successful installation of software, a window is opened to you that will check the pre-requisite in your system. You have to click on Next button to proceed further.

Step 2:- Click on the Split PST option from the window.

Step 3:- Select the version of Outlook among the given two options and select the split option among those four.

The PST file can be split by four methods, by Size, date, year and Folder. Select the desired option among them and click on the Next button.

Split by Size – By defining the split size of PST in GB, the file will be split into multiple files having the same size.

Split by Date – A large sized PST file can be split by date and a single file will be divide on the basis of ‘of and prior’ of specified date and ‘after’ date.

Split by Year – This option helps you to divide the PST files by yearly; a single file for each year will be created including the given years.

Split by Folder – PST splitter allows you to divide the PST file based upon the existing folders such as a separate PST file will be created for each existing folder.

Step 4:- By choosing any of the above option, click on the Next button.

Step 5:- Now select the PST file to be split by clicking on Browse button.

Step 6:- Choose the range for previously selected split option.

Step 7:- Select the destination path where the spitted PST file will be saved on your system.

Step 8:- Click on the Next button and then click on Split tab.

The software pane shows you the status of processing, and a dialogue box will be visible in front of you after completion of process.

Step 9:- If you want to see the CSV file for the details of split process, click on Compare PST.

Step 10:- Click on Cancel to close the software window.

After performing all the above steps, you can easily split your large sized PST file into multiple files to prevent the data loss and corruption. The files are saved in your system and you can use it for future use.

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About: Mike

Milind Koyande loves to work on new technologies specially virtualization and troubleshoot server problems. I’m an avid photographer and love to spend my free time close to nature, trying to capture its glory on my camera.

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