Microsoft Outlook is the brilliant email How to Reduce Outlook PST File Size to Avoid Oversized PST Error

Diminish the Chances of PST Corruption – Apply PST File Size Reduction Techniques

How Microsoft Outlook Stores Email Items?

Microsoft Outlook stands as an exceptional email client and manager, offering a comprehensive suite of services for email and information sharing. These services include calendaring, task management, contact management, and email handling, among others. Notably, Outlook boasts an outstanding collaborative platform, featuring seamless integration with Exchange Server. This integration brings dynamism and a wealth of exclusive benefits to the Outlook client.

Microsoft Outlook organizes and securely stores email items shared among users across various platforms, including Exchange Server, standalone machines, and within the Outlook application. It efficiently duplicates these email files, placing them in the PST and OST folders, designed for exclusive use in online and offline modes, respectively. You can readily locate the PST and OST files on a standalone machine at the following directory:

C drive: \ Users \ <user account name> \ AppData \ Local \ Microsoft \ Outlook (For Windows 8)

It's important to understand that OST files serve as duplicates of email data stored on the Exchange Server. These OST files automatically synchronize with the Exchange Server to update and share any email changes made while the Exchange Server was disconnected from MS Outlook.

Why & How to Reduce the PST File Size?

It has been observed that the buildup of email items within PST and OST folders can significantly impair the performance of Exchange and Outlook services, occasionally resulting in severe data corruption. Furthermore, you may have heard of the detrimental consequences of Outlook PST files becoming excessively large, potentially causing the loss of an entire email archive in a matter of seconds. To proactively prevent such catastrophic incidents, it is advisable to diligently monitor PST file sizes and, when necessary, compress them. Let's explore how this can be effectively achieved.

Utilize Outlook Compact Functionality

Get started with the following intuitive steps:

  • Before proceeding, check and delete the unwanted email items of Outlook profile.
  • Switch to the Folder List View by clicking the Folder List icon from the navigation pane.
  • Right-click Deleted Items from the Navigation Pane. Click the Empty Folder option.
  • Click File Account Settings Account Settings.
  • Select the Data Files tab, and then click the Settings option.
  • Click the Compact Now option.
Apply Outlook Archive Option

To effectively tidy up your less critical Outlook email elements, it's advisable to develop a routine for archiving PST email items using the following straightforward steps:

  • Open the Outlook email client if not opened already.
  • Click the File option from the Navigation Pane, and then select Info.
  • In the Mailbox Cleanup field, select Cleanup Tools followed by Archive.
  • In the Archive dialog box, browse the Outlook folder which you want to archive, and then click OK.
Adopt Practice of Saving Individual Emails

One can function plethora of tactics to keep the PST file size in limits. One of the tasks user must perform is the restoration of PST mail items in an individual email items, i.e. MSG file. Let us see how it can be performed:

  • In the MS Outlook email client, select the required email item.
  • In the Menu bar, click the File option, and then select Save As.
  • Select the desired location to save file and Select Outlook Message Format from the Save as type drop-down field.
  • You can check the saved email message by opening from the saved location.
Discard Email Duplicity

Eliminating duplicate Outlook email items from your Inboxes and folders can significantly assist in managing the influx of unwanted emails and preventing the PST file size from becoming unmanageable. To carry out the process of identifying and removing duplicate emails, you should start by examining the emails you've sent, which are typically stored in the Sent Items folder and may contain multiple instances of emails with attachments. To pinpoint duplicates, you can organize the email items based on the recipient criteria. Once organized, you can select and delete any email items that appear more than once, thereby decluttering and reducing the size of your Outlook mailbox.

By adhering to the strategies outlined above, users can effectively reduce the excessive size of their PST file, thereby preventing potential PST file corruption. Nevertheless, given that users are often preoccupied with their existing tasks and responsibilities, they may struggle to allocate sufficient attention to the management of Outlook PST file sizes, ultimately leading to PST corruption. In such situations, it becomes the sole responsibility of the user to address PST corruption in order to mitigate any risk of data loss. We strongly recommend employing a reliable third-party PST recovery tool to skillfully recover PST files and restore data integrity.


Kernel for Outlook PST Repair is a robust application designed to restore corrupted PST email items from a range of error scenarios, including the notorious 2 GB PST file size issue. This software provides an array of advanced features for exporting recovered PST files to multiple email servers, web-based email applications, cloud services, and various alternative file formats.

Following these option users will retrieve 100%complete PST files and can then access Outlook files flawlessly.