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Summary: Managing Outlook’s performance when dealing with large PST files is essential. This article discusses strategies for addressing performance issues caused by large PST sizes. It covers optimizing Outlook settings, archiving, compacting, and using third-party tools for efficient management and a smoother email experience.

Microsoft Outlook is designed to operate seamlessly, without interruptions or delays. However, if you start experiencing issues such as slow performance, interruptions, or delays while sending, receiving, or deleting emails, it’s often an indicator that your data file has become sluggish. This slowdown is typically attributed to the growing size of the PST file. A PST file can house multiple mailboxes and is capable of accommodating several gigabytes of data. When Outlook’s performance significantly deteriorates, it’s crucial to explore methods to effectively reduce the size of the PST file.

In terms of the recommended size for PST files, Microsoft offers the following guidelines:

  • Small PST files (up to 5 GB size) When PST file size is up to 5GB, Outlook performs very well irrespective of its environment.
  • Optimum sized PST files (5 to 10 GB size) If the size of PST file is between 5 GB to 10 GB, Outlook provides a good user experience in environments with fast hard disks and plenty of RAM. However, performance will be affected if the hardware is not sufficient. So one has to be careful while using Outlook in older generations of PCs.
  • Default size of PST files (25 GB size) The default size for a UNICODE PST in Outlook 2010 and later is 25 GB.
  • Maximum size of PST files (50 GB) The maximum size for a UNICODE PST file in Outlook 2010 and later is 50 GB. However, one can change this value by editing the registry entries.

Configure the PST file size limit in MS Outlook

Let’s now explore the method of setting the PST file size limit in MS Outlook, which involves modifying the Windows Registry. While this method allows users to configure the file size limit in Outlook, it’s important to note that registry modification carries some inherent risks.

How to reduce the size of PST files?

To enhance Outlook’s performance, it’s crucial to reduce Outlook mailbox size. This can be achieved by removing unnecessary items and subsequently compacting the PST files.

  1. In Outlook, right-click on the Deleted items folder and then click Empty Folder.
  2. Now, click File > Account settings > Account Settings.
  3. Under the Data Files tab, choose your Outlook data file and click Settings.
  4. In the Outlook Data File dialogue box, click Compact Now. Click OK.
  5. By this, your PST file will be compacted.

Compress & compact PST files in easier way

When the manual method for compressing the PST file size falls short of delivering satisfactory results and the PST file remains excessively large, it’s advisable to utilize Kernel PST Compress & Compact software. This tool effectively reduces the size of the PST file without altering the structure of the data within the mailboxes. After compression, you can continue using the PST file seamlessly.

Kernel for PST Compress & Compact