How to Split Large PST Files for All Outlook Versions

What Is a PST File and Its Size Limits

A PST (Personal Storage Table) file stores Outlook mailbox data locally. However, Outlook applies size limits.

• Outlook 2002 and earlier: 2 GB limit
• Outlook 2007, 2010, 2013, 2016, 2019, 2021: 50 GB limit
• Microsoft 365 Outlook: 50 GB recommended limit

Once the PST file crosses safe limits, Outlook may stop responding. Therefore, splitting the file early is always a smart move.

Understanding the Need to Split Large PST Files

When you manage large PST files, it becomes crucial to keep Outlook running smoothly and prevent data loss. Here are the main reasons why splitting PST files is necessary:

• Large PST files slow down Outlook performance.
• Searching emails and switching folders becomes slower.
• Oversized PST files increase the risk of corruption.
• Corrupted PST files can make emails and attachments inaccessible.
• Backing up or restoring large PST files takes more time.
• Migrating huge PST files to another system is difficult.
• Large PST files can cause Outlook crashes or freezes.
• Splitting PST files improves performance and protects your data.

By understanding these challenges, it becomes clear that why you need to compact PST file Outlook. It is essential for efficient and safe email management.

How Many Ways Are There to Split PST Files

There are two main ways to split large PST files:

1. Manual method using Microsoft Outlook
2. Automatic method using a professional PST splitting tool

Both methods work differently. So, choosing the right one depends on mailbox size, technical skills, and time availability.

Method 01: Split Large PST File Manually Using Outlook

Outlook does not offer a direct “split PST” option to break Outlook PST file. However, users can manually reduce PST size by creating new PST files and moving data. Follow the given steps to divide PST file into smaller parts:

1. Launch Outlook on your computer to begin the process.
2. Then, click on File > Account Settings > Account Settings to access the PST File.
3. In the Account Settings window, select the Data Files tab to view all PST files.
4. Now, click on Add to create a new PST file. Choose a location on your computer.
5. After that, select the large PST file and drag it into the new PST file.
6. Also, you can use the Move to Folder option for better organization.
7. Repeat this process as necessary until the original PST file size is reduced.

Limitations of the Manual PST Splitting Method

However, the manual method is free; it has several drawbacks that users must consider:

• Moving emails manually, especially for large mailboxes, can take hours or even days.
• Drag-and-drop operations may result in misplaced emails or missed folders.
• Moreover, large PST files may cause Outlook to freeze or become unresponsive.
• Along with that, some email attachments may not transfer properly.
• Mistakes during manual splitting may lead to permanent loss of emails.

When PST files contain thousands of emails, the manual method becomes unreliable. Outlook may freeze during data movement. Hence, professionals and business users prefer automated solutions to avoid these risks.

Method 02: Use the Automated PST Splitter to Split Large PST Files

Aryson PST Splitter is the expert-recommended solution to Split PST file Outlook 2026 / 2021 / 2019 / 2016 / 2013 / 2010, along with all earlier and major versions. It can handle large PST files without compromising data integrity. Moreover, it supports both ANSI and Unicode PST files, compatible with PSTs created in any Outlook edition. Other notable features include a user-friendly interface, fast processing, and zero risk of data loss. Along with that, it provides different filters to manage oversized PST files:

• Split PST by Size: Divide large PST files into smaller files based on specific size limits to prevent Outlook crashes.
• Split PST by Date Range: Create separate PST files for emails received within a particular date range.
• Split PST by Folder: Maintain the original folder hierarchy while splitting files.
• Split PST by Sender or Subject: Extract emails from specific senders or based on subject lines.

Follow these Steps to Split Large PST file in Bulk

• Install the Aryson PST File Splitter on your Windows system and launch it.
• Use the Add File or Add Folder option to load the PST file you want to split.
• Select a splitting method such as by size, date, year, folder, or sender.
• Now, you can select a destination folder to save the new PST files.
• Apply filters or include/exclude particular folders to customize the split.
• Click Split to reduce PST file size into smaller, manageable files.

Within minutes, your large PST file will be split into several smaller files, making Outlook more responsive and easier to manage.

Conclusion

Large PST files affect Outlook performance and increase corruption risks. Manual ways to split large PST file may help in limited cases, but they involve effort and uncertainty. In contrast, automated split software provides a structured and reliable splitting approach that keeps mailbox data safe and Outlook responsive. With the right method, users can manage PST files efficiently across all Outlook versions and avoid future issues.

FAQs About Splitting Large PST Files

About The Author:

Harshita Sachdeva

Harshita Sachdeva, a professional technical writer at Aryson Technologies, specialize in delivering clear, hands-on documentation for data management, migration, and recovery solutions. With a meticulous, reader-first approach, I break down complex technical processes into simple, actionable content - helping IT professionals and decision-makers tackle challenges efficiently.

Related Post

Upload 10000+ Emails PST to Office 365: Easy Guide for 2026

Quick Solution to Encrypt Outlook PST File Effortlessly

My Outlook .OST File Disappeared After Changing IMAP Server: Best Method