How To Reduce OST File Size In Outlook 2019/2016/2013?

The average Outlook email file size is around 100MB. Anything above that and you start to feel the effects on performance, which can lead to slower response times when opening emails or attachments. Here’s how you can reduce your OST file size in 3 steps.

The “the outlook data file has reached the maximum size office 2016” is a problem that many users have been facing for quite some time. There are ways to reduce the size of your OST file in Outlook 2019, 2016 and 2013.

How To Reduce OST File Size In Outlook 2019/2016/2013?

Summary- This article explains how to minimize the size of an OST file in Outlook 2019/2016/2013. It describes how to decrease the size of an OST file manually, step by step. You’ll also learn about professional applications that may help you minimize the size of huge OST files.

An OST file is an Outlook offline storage file that stores mailbox data in offline mode. Without an internet connection, you may create emails and other data items in an OST file. A Personal folder file (PPF) is included in the OST file format, which holds emails, contacts, calendars, and other information.

The following items may be found in the OST file:-

  • Emails, contacts, calendars, notes, tasks, diaries, and other data from your inbox.
  • Favorite public folder items and hidden things
  • Additional mailboxes related with the exchange account’s shared folders.

What Causes an Oversized OST File?

The OST file might become huge due to the vast amount of data it contains. It’s difficult to handle large OST files, which causes damage and corruption to existing files, causing Outlook data to suffer. The storage capacity of a file is determined by the Microsoft Outlook application’s version. Now let’s talk about how to lower the size of an OST file with routine maintenance.

Outlook Maintenance to Reduce the Size of the OST File

To keep the data safe and secure, the mailbox folder must be maintained on a regular basis. There is a risk of data corruption and harm if the mailbox folder is not maintained on a regular basis. The following are various methods for determining the size of an OST file: –

  1. Delete any unwanted emails and other stuff from your inbox.
  2. Empty the trash and spam folders on a regular basis to keep the OST file size down.
  3. If data items need to be removed from the mailbox, do a hard deletion.
  4. Ensure that mailbox folders are compressed on a regular basis.

These are some of the reasons why the OST file in Outlook must be maintained on a regular basis. Now, go to the most effective method for reducing the size of an OST file.

How to Recover Oversized OST Files

We’ll go through the best ways to minimize the size of an OST file in this article. These approaches are simple to use and provide effective and consistent outcomes.

  • In Outlook, disable all add-ins.
  • Data from an OST file should be archived.
  • Reduce the size of the OST file
  • Microsoft Outlook can help you minimize the size of your OST file in a professional manner.

In Outlook, disable all add-ins.

Outlook’s add-ins cause a slew of problems for its customers. To prevent this kind of malfunction, disable the

Add-ons are a fantastic alternative. To deactivate the Add-Ins, follow these steps:-

    1. Open Microsoft Outlook, choose the needed option from the File menu, and then click Add-Ins.

click on add in

    1. Then, under View and Manage Microsoft Office Add-ins, choose the COM Add-in and press the Go button.

hit on go

    1. Select Ok after unselecting all of the Add-ins that aren’t presently in use.

click ok

Data from an OST file is archived.

By archiving the OST files that are no longer needed, you may free up some space and lower the size of your OST files. The huge OST files may be archived to save up space and avoid file corruption or destruction.

How to Archive Data from an OST File

    • Click on the File tab in Microsoft Outlook.
    • Select Mailbox cleaning from the cleanup tools menu.

click on cleanup tool

  • These are the two alternatives that are now accessible to you:-
  • By selecting the Auto Archive option, you may move older items in your inbox to an archive folder.
  • Delete things from the deleted items folder by selecting the empty option.

The OST file is compressed.

Follow these procedures to reduce the size of your OST files:-

    1. Remove things that don’t need to be compressed or kept in the mailbox.
    2. In the Navigation pane, right-click on the folder in the folder list view, choose Deleted items, and then Empty folder.
    3. Click the File tab in Microsoft Outlook, then the Account setting, and then the Account Setting option.
    4. Select the data file to be compressed from the Data File tab, then click Settings.

click on cleanup tool

  1. Choose the Advanced tab in the opening dialogue box, then click Outlook Data File Settings.
  2. The last step in the Outlook Data File Settings dialogue box is to click Compact Now.

These are some manual techniques for reducing the size of an OST file, but they have some drawbacks, such as the possibility of losing data if an OST file becomes corrupted or destroyed owing to its large. To bypass these limits, I propose that you minimize the size of your OST file using another means.

An expert solution to the issue of an oversized OST file

The SysInfo OST splitter program is a completely risk-free application. It divides the Oversized OST file into many pieces based on date, size, email type, and other factors. This program offers both professional and non-professional users a number of useful functions. It is completely safe and decreases the size of OST files in a short amount of time.

The following are some of the more sophisticated features of Professional Software:-

  • Splits huge OST files: The OST splitter allows you to separate a large OST file by Date, Name, Size, Email Category, and Year.
  • Provide the opportunity to repair corrupted files: Before splitting huge files, this utility gives you the choice to fix corrupted and damaged files.
  • Users do not need to install Microsoft Outlook to divide OST files: Users may split OST files without installing Microsoft Outlook on their PC.
  • Separate the freshly produced OST file from the previously archived OST files:- This utility also allows users to partition freshly produced OST files and archived OST files among themselves.
  • After separating the Oversized OST files, create a new folder to store the OST files in. The generated OST data file may be saved in a new folder with this utility.


This blog discusses the reasons why OST files grow in size and how to minimize OST file size. This article will show you three manual approaches for repairing large PST files. Professional Software is also available for more trustworthy and efficient outcomes.

Question Frequently Asked

What causes the size of OST files to be so large?

Emails, calendars, diaries, contacts, tasks, and assignments are all stored in an OST file, which might become enormous because to the vast amount of data. As a result, it’s difficult to handle large OST files, which might cause damage and corruption.

How can I determine the size of an OST file?

The following are some ways to determine the size of an OST file:-

  • Select Data File Properties from the context menu when you right-click on the folder you wish to inspect. Select Properties in Microsoft Outlook.
  • Now you may choose the folder’s size.
  • In the Folder Size box, the size of the folder and its subfolders is shown in kilobytes.

The “increase ost file size outlook 2019 to 100gb” is a question that has been asked quite often. The article will show you how to reduce the size of your OST file in Outlook, 2016, and 2013.

Frequently Asked Questions

How do I change the OST size in Outlook 2016?

A: In Outlook 2016, go to the File menu and select Options. Select Advanced options in the left pane under Mail Setup. On the right hand side of this screen are three columns with icons next to them; one is titled Export Format, another is Import Format. The last column will have a drop-down box labeled File Extension that includes .wav or .mp3 files as options for your preference.

How do I fix Outlook OST has reached maximum size?

A: For some users, their Outlook OST has reached the size limit and this can cause issues with the program. To resolve this issue, try to delete large files from your email account that arent needed anymore or unsubscribe from any subscribed emails that you no longer want.

Can you compress an OST File?

A: There is no way to compress an OST. OST files are uncompressed RAW audio data. That said, you can use a program like Audacity or Sony Sound Forge in order to reduce the overall size of the file that it takes up on your computer by reducing its sampling rate and bit depth settings.

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