Fix Outlook Oversized OST File Problem Fast

  

Mark Regan
Published: April 25th, 2025 • 7 Min Read

Understanding how an OST file works and potential causes associated with Outlook Oversized OST File Problem is crucial to fix as it can affect Outlook performance. In the upcoming sections, we will explore signs of the Outlook OST file being too big, their impact on Outlook, and also offer tried and tested approaches to fix OST files too large.

Microsoft Outlook OST(Offline Storage Table) contains crucial information as it contains emails, contacts, calendars, and other Outlook data. It allows users to access and manage data without having connectivity and it will reflect on the server when internet connection is restored. But exceeding data storage limits can affect Outlook performance and Outlook Oversized OST file problems.

If your OST file gets corrupted due to oversize then you can use OST to PST Converter to restore and split into multiple PST files as per required size. OST files created when configured with Exchange Server and it also offers various flexibility and convenience, they can grow to large size over time, especially for users with heavy email traffic or who store large attachments.

Signs That Your OST File is Oversized

• One of the first indications that Oversized OST file is noticeable slowdown in Outlook performance. If it takes to load your inbox, open emails or switch between folders your Outlook OST File is too big.
• You may face error messages such as Outlook data file cannot be accessed or Cannot open your default email folder then these errors appear due to Outlook OST file too big.
• If you experience difficulties syncing your Offline data with Exchange Server, such as emails not updating, missing calendar events or delayed email delivery, then Outlook Oversized OST file Problem
• OST files too big consume considerable storage on your machine. If you receive warnings about low storage, particularly in the drive where the OST file is located, this could result in a bloated OST file.
• If Outlook frequently crashes, freezed or becomes unresponsive when trying to perform actions like searching, opening emails, or applying filters, the OST file may have become overloaded with data.
• If searches with Outlook take longer than usual, especially looking for emails or other data it could indicate that the OST file is too large to search efficiently.

Common Causes of Oversized OST Files

• Regularly sending and receiving emails with large size attachments can quickly fill an OST file specially for customer support, sales or marketing departments.
• Emails with bulk attachments like high-resolution images, videos, presentations, or zipped files can make Outlook OST files too big.
• Accessing several shared mailboxes, calendars or public folders in Outlook can cause data to be cached locally, thereby expanding OST file size.
• Not archiving old emails or cleanup necessary messages and folders causes OST files to grow unchecked, especially when deleted items and sent items folders aren’t cleared regularly.
• If Outlook is set to retain emails for an extended period without archiving or deleting your OST file will accumulate more data, making it grow beyond optimal size.

How to Fix Outlook Oversized OST File Problem?

If your OST file grows too large, it can slow down performance, causing sync errors or even lead to data corruption. Below are effective methods to fix Outlook oversized OST file problem

Method 1. Compress OST File

1. Firstly, Open Outlook and navigate to Account Settings.
2. Then, Click on Data files and choose your OST files.
3. Now, Press on Settings and under the advanced tab click Outlook data file settings.
4. Finally, Click on the Compact Now button.

Method 2. Archiving Old Emails

1. Now, Open Outlook and click on the file.
2. Here, Press on options and hit on Advanced.
3. After that, Hit on Auto Archive Settings and choose auto-archive, folder age and archive location.

Method 3. Delete Unnecessary Emails

1. First, Open Outlook and sort emails by size.
2. Next, Use Search folders and click on Large Mail.
3. Here, Empty deleted items and Junk folder regularly.
4. Thereafter, Save Attachments to your computer and remove them from your emails.

Steps to Fix Outlook Oversized OST Problem

1. Download and run suggested software on your system.
2. Select Convert configured Outlook mailbox data or let me select the OST file.
3. Now OST mailbox folders as you want to split.
4. Choose Split options and select the destination path.
5. Choose Advanced settings for splitting and click on Split.
6. Software shows you live progress and also pop messages when the process gets finished.

Notable Features of Suggested Software

• It can break OST emails, calendars, journals, contacts and all other data available in OST file.
• This software is specially known for maintaining hierarchy and email components such as cc, bcc, too, receiver, subject and more.
• It allows users to preview all folders and subfolders for specific OST mailbox selection.
• You can also use advanced filter such as check to change split size, check to create separate or common files, export only selected Outlook items and so more
• This wizard has been specially designed for both business and non-technical users to easily perform with having advanced technical skills.

Let’s Wrap Up

When the Outlook OST file is too big then it affects productivity. Due to these we have filtered a simple solution by compressing, archiving, splitting OST file to fix Outlook Outlook Oversized OST file Problem. After opting for a solution you fix this issue and it doesn’t come in future as you can manage the OST file and don’t lose any crucial information from your OST file.