How to Deal With Too Large PST File > 50GB?

Updated on January 13th, 2021

Kuljeet Singh

Summary: An oversized Outlook Personal Folders (.pst) file can get corrupted and make the data inaccessible. This blog discusses ways on ‘how to deal with too large PST file greater than 50 GB’. It also explains what you can do if a large PST file turns corrupt. And how Stellar Toolkit for Outlook can help you overcome all Outlook issues by allowing to split, compact, merge, repair, and recover Outlook data file.


Outlook 2010, 2013, 2016, and 2019 support PST files of a maximum of 50 GB. An Outlook PST file exceeding the 50 GB size limit is prone to corruption and may result in ‘cannot open the PST file’ error. In case the PST file gets corrupted, you will not be able to access the PST file and its contents unless the file is repaired. Also, you must know ways to manage an oversized PST file to prevent it from getting damaged or corrupt in the first place.

Ways to Manage Large PST File Manually

You can manage your large-sized PST file manually by following different ways, as mentioned below:

  • Split the PST file: To manage large-sized PST file, you can split it into multiple small-sized PST files. However, Outlook does not provide any inbuilt utility or feature to split a large-size PST file. Nonetheless, you can reduce PST file size by using Outlook’s ‘Archive’ or ‘Import/Export’ option. These options do not split the PST file but move mailbox data from one PST file to the other.
  • Compact the PST file: In Outlook 2013 and above versions, you can use the ‘Compact Now’ feature to remove deleted data space. This helps compact or compress the large-sized PST file. Outlook automatically compacts its data file, if it contains more than 20% of unused space. You can also manually compact the PST file by following these steps:
  1. In Outlook, navigate to File > Account Settings > Account Settings.
  2. In Account Settings window, click the Data Files tab, and then click the .pst file that you want to compact.
  3. Next, click Settings.
  4. In Outlook Data File box, click Compact Now, and then hit OK.
  • Remove duplicate data from the PST file: Large number of duplicate emails also results in oversized PST file. In that case, removing duplicate emails can help resolve the issue. However, there are various reasons that lead to duplication of emails, including incorrectly configured Rules, short Send/Receive intervals, improper Mailbox settings, incorrect Account setup, third-party anti-virus scanner, etc. And so, you will need to address the actual cause behind the problem to remove duplicate email messages.

Read this: Steps to Remove Duplicated Email Messages in Outlook 2016

What To Do If the Large-sized PST File Gets Corrupt?

You can use Outlook’s inbuilt ‘Inbox Repair Tool’ (Scanpst.exe) to repair your corrupted Outlook PST file. The tool is designed to fix PST file errors.

Read this: Download Free Scanpst.exe to Repair Outlook PST File

If the built-in repair utility fails, use a specialized PST file repair tool to repair severely corrupt PST file and recover all the file content.

Limitations of Manual Solutions

  • Finding different solutions to resolve different Outlook issues requires time and effort.
  • Implementing different solutions to deal with an oversized PST file, like splitting, compacting, and removing duplicate data, can be lengthy.
  • Inbox Repair tool may fail to repair the damaged PST file in case of severe corruption.

An All-in-One Solution for all Outlook Issues

With modules such as Repair Outlook, Split Outlook PST File, Compact Outlook PST, Remove Duplicate Emails, Recover Deleted Emails, Convert OST to PST, Merge Outlook PSTs, and Recover Outlook Password, Stellar Toolkit for Outlook is a befitting solution for all Outlook issues. Further, the user need not to find different solutions for different issues.  

Stellar Toolkit for Outlook

                                              Figure: The main interface of Stellar Outlook Toolkit

For dealing with an oversized Outlook PST file, use the following modules of Stellar Toolkit for Outlook.

  • Split Outlook PST File – With this module, users can split a single PST file into multiple PST files by Size, Date, Email ID, and Mail Folder. Choose any of these to split large-size PST file.
  • Compact Outlook PST – This module allows users to compress the PST file. On using this, size of the PST file reduces, and it becomes less prone to corruption.
  • Remove Duplicate Emails – Using this module, users can remove duplicate emails from the PST file. This reduces the PST file size.

To repair a corrupt PST file, use the following module:

  • Repair Mailbox: This module allows users to repair a damaged Outlook PST file and makes the PST file usable. Further, users can easily access their data items, such as emails and their attachments, contacts, calendars, tasks, journals, etc.

End Note

Stellar Toolkit for Outlook is one of the best solutions for dealing with an oversized PST file. The reason being, you won’t need to execute the lengthy and complex processes to resolve different issues that may crop up due to large-sized PST file. With one solution, you can do all: repair damaged PST file, split Outlook PST, compact Outlook PST, and remove duplicate emails from the PST file. Apart from this, it can convert multiple OSTs to PST files, recover deleted Outlook emails, merge multiple PST, and remove lost password from PST.

See what Experts say about the Software:


Also Read:

Remove Duplicate Emails in Outlook

Outlook Slow in Receiving Emails

Steps to merge multiple PST files

Recover Lost Personal folder in Outlook

About The Author

Eric Simson

Eric Simson is an Email Platform Consultant and is associated with Stellar Data Recovery from last 6 years. He writes about the latest technology tips and provides custom solutions related to MS Outlook, MS Exchange Server, Office 365, and many other Email Clients & Servers. 

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  1. The software splits the file both ANSI and UNICODE formats. I can say that this software is helping me to save my productive working hours.

    1. Hi Harry, we are happy to help you. You can also subscribe to our blogs to receive the latest technical updates.

  2. Hello,

    I want to split my organization .pst large file (around 24.7 GB) into smaller and manageable PSTs, based on specified PST split criterion, such as Date (year wise).

    There is any way to split pst file. I need easiest and fast way to do this function.

    1. Hello Vicente,

      By using the “Split Outlook PST” module, you can apply different criteria to PST file. For better understanding, you should try at least a free demo of the tool.

  3. Does anyone know of any good programs that can split a large pst file (about 44.8 gb) don’t ask me how it got that big, its not mine, it’s just some user I have to support. This is Outlook 2007.


  4. My Outlook archive .pst file is a little over 55.6 GB. I have over 10 years worth of data in there for my business. Today I faced this issue that .pst file is not opening. Now how can I recover my data?

    Please help me!

    1. Hi,
      Your problem is related to damage in Outlook data file. You should use “Repair Outlook” module of Stellar Outlook Toolkit.

  5. I’ve been using Outlook 2010, now I’m using Outlook 2013. My PST file is very large 45 GB. I have auto archive set for 30 days.

    Is there any way for me to break this PST file into smaller parts and still retain the data in them?

  6. Why should I care about too large PST file size? I am using Outlook 2016 and its default file size limit is nearby 50GB.

    1. A bulk size PST file is responsible for low productivity/slower speed of Outlook email application. We should break a large PST file into smaller parts.

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