How to Reduce Outlook PST File Size Without Splitting

  • Written By  

  • Updated on May 2nd, 2023

Summary: MS Outlook users know how large a PST file can grow over time and become vulnerable to corruption. So it is important to manage PST files from time to time to keep them safe and safe. Therefore, this write-up will explain the various ways to reduce Outlook PST file size. We will also include a professional PST Compress tool to reduce the size of Outlook PST files automatically. Download Now   Purchase Now

Why Need to Reduce the Size of Outlook PST

All your emails, attachments, contacts, calendar events, and other data are kept in your mailbox when you use Microsoft Outlook. As you use Outlook over time, the size of your mailbox may increase and result in a variety of problems, such as

  • Performance declines: Outlook may function more slowly and become less responsive as your mailbox size grows, especially while searching, sending, or receiving emails.
  • Crashing and freezing: If the recommended mailbox capacity is exceeded, Outlook may crash or freeze when you attempt to complete an operation.
  • Synchronization issues: Large mailbox sizes might lead to synchronization problems, leading to missing or duplicate emails if you use Outlook across different devices.
  • Risk of data corruption increasing: Data corruption, which can result in data loss, is more likely the bigger your email is.

It’s advised to regularly manage your mailbox size by archiving old emails, eliminating pointless attachments, and compacting your mailbox to prevent these problems. Additionally, you may utilize Outlook’s AutoArchive feature to automatically move outdated documents to an archive folder and think about employing an external email archiving service to store crucial communications for the long term. So go through the methods to compact the size of PST files without splitting.

Methods to Reduce Outlook PST File Size Without Splitting

There are many ways to reduce the size of a PST file, so in this section, we will explain some of them that are effective as well as efficient. Such as:

  1. Archive old emails
  2. Eliminate or delete useless attachments
  3. Compacting your mailbox
  4. Activate the AutoArchive feature
  5. Use Professional Software

Method 1: Archive Old Emails Using Outlook

MS Outlook provides an option to archive old items as a clean-up feature, so follow the steps below to use this method.

  1. Open Outlook and go to the File tab.
  2. Click on Tools and select the Clean Up Old Items option.
  3. Choose the folders you want to archive.
  4. Set a date to archive emails older than your requirements.
  5. Select the destination to save the resultant file by clicking on the Browse button.
  6. Finally, click on the OK button to finish the process.

Method 2: Eliminate or Delete Useless Attachments

The best strategy is sure to delete huge emails. You may manage Outlook attachments by using a methodical strategy rather than arbitrarily removing huge files. The steps are as follows:

  1. Start Outlook. Click the Search folder in the folder list, then pick the New Search folder.
  2. Select Large Mail under Organizing Mail as you move down the list. Under Customize Search Folder, click Choose.
  3. Enter a size (for instance, 8000 KB) in the “Show mail greater than” box. Click OK to proceed.
  4. A folder called “Larger Than 8000 KB” is created under Search Folders after you click OK once more. Emails larger than 8000 KB will automatically be added to this newly formed folder.

Method 3: Compact Your Mailbox

In order to eliminate whitespace and condense the size of the mailbox, Outlook offers the option to compress or compact Outlook PST files. the following steps:

  1. Access Outlook by clicking File > Account Settings > Account Settings.
  2. Choosing the PST file from the list after clicking “Data Files”
  3. Choose “Outlook Data File Settings” from the Settings>Advanced menu.
  4. Select “Compact Now” from the menu.

By doing this, you will be able to reduce Outlook PST file size by removing the whitespace.

Method 4: Enable AutoArchive Setting

Enabling the AutoArchiving option helps you manage the amount of space in your mailbox or on the email server you are using by automatically shifting items to an archive folder, so follow the steps below to use this technique.

  1. Open Outlook and click on the File tab >> Options.
  2. Select Advanced and click on Auto Archive Settings.
  3. Check the Run Auto Archive option and set the number of days as per your needs, and then click OK.

These are all straightforward tricks that help you to shrink PST files. However, these methods have some disadvantages that can lead to file corruption. Moreover, they don’t properly compact or reduce the size of PST files and take too much time to process. Furthermore, you also need technical expertise to operate the above procedures. So to avoid these problems, we are providing you with a better approach to reducing PST file size without Outlook.

Method 5: Reduce Outlook PST File Size Using Automated Software

PST Compress Tool is trustworthy software that allows you to reduce your Outlook mailbox size without MS Outlook installation. It provides a feature to select a single PST file or a folder containing multiple PST files at once. You can also remove all the attachments to compact the size of the PST files.

Step-by-Step Guide to Compress Outlook PST File

  1. Download and run the PST Compress Tool.
  2. Click the Select Files button to add single or multiple Outlook Data files you need to compact.
  3. Preview the details and mark the folders you want to compress. and then click Next.
  4. Select the Compress option according to your requirements.
  5. Utilize the built-in features facilitated by the software.
  6. Click the Start Compression button to start the reduction process of PST files.


This blog has described the numerous techniques to reduce Outlook PST file size. Four manual solutions are capable of compacting your PST files. However, they also consist of various limitations that can cause several problems. So to avoid any mishappening, we have also provided you with a professional method that allows users to freely compress their PST files with 100% data integrity. But choosing any of the above solutions on your continent is up to you.

About The Author:

Adom Smith is a DataRecoveryHelp Technology Writer. He is a technology enthusiast with over 3 years of experience in Data Recovery, IoT, Artificial Intelligence, and Robotics. He enjoys researching and sharing DIY solutions as well as tips and tricks for resolving Windows technical issues.

Realted Post

© Copyrights 2020-2023 by Data Recovery Help - All Rights Reserved