How to solve Error ‘The OST File has Reached the Maximum Size.’

Amrita Choudhary

Published On - October 19, 2022

Summary: – OST file has reached its maximum size error message appears when the size of the OST file size comes close to its configured file size or threshold limit. Here, we will discuss the easy and practical solutions to help users resolve the OST file size problem in Windows Outlook.

Microsoft Outlook is a widely used email client for sharing important information and messages. OST file is handy for the offline storage of Outlook data, and this feature makes Outlook special. OST files can also be seen as the backup of Outlook data on the hard drive for offline use. OST or Offline Storage Table is a carbon copy of the user mailbox on the Exchange Server. It saves data locally on the system and syncs the Outlook changes to the user mailbox on the server.

Outlook users face lots of issues in everyday life. Sometimes, the Outlook OST file size limit reaches the maximum level, and you won’t be able to store more data in it. Consequently, Outlook will not allow you to send or receive emails.

It is an alarming situation for all MS Outlook users. At that time, only one option is left – deleting contents from the OST file.

So, we are giving information here regarding the reasons behind this error and a step-by-step process to tackle this issue. So, keep reading here.

Some reasons why the OST file has reached the maximum size

• Limitation of the file format: – Sometimes, the file format used in Outlook has a size limit that can fill within a few months. The ANSI format has a size limit defined as 2GB which can quickly fill with large attachment files and data. However, this issue is there in the earlier versions only; recent versions of Outlook are not affected by this issue.
• Registry issues due to two versions: Installing two different versions of Office, like 2007 and 2013, on the same system may cause errors. Some registry entries might not get updated properly, so OST errors may arise.
• Reaching the size limit: In the recent versions of Outlook, the OST is a file having UNICODE format with a higher limitation like 20GB. However, it can also be filled with regular usage, causing OST size issues.

Techniques to resolve this error

To check the size of the OST file, we are providing different solutions:

Manual solutions

1. Archive the email data
   Archiving Outlook items is the most recommended and effective solution. It moves the original data to a different file to fix the Outlook error, i.e., the Outlook data has reached the maximum limit. Archive files can also be used with Outlook at times of need. If you have a large OST file, then this method helps you to reduce OST size significantly.
   Follow the given steps: –
   • In Outlook 2016 and 2019, go to the File menu.

   Note: In Outlook 2013 and the below versions, go to File >> Cleanup Tools >> Archive.

   • Go to Info >> Tools, and then go for Clean up old items.
   • Then opt for Archive this folder and all subfolders option from there.
   • Select Personal Folders to archive all Folders, or select the folders you want to archive from the list.
   • Select the ‘Archive items older than:’ column and select a date to archive older items.
   • Then select a location. Finally, click on the OK button.
2. Mailbox cleanup
   You can make space easily by reducing your older email messages. This will also help tackle the issue with OST file size.
   • Open your Outlook.
   • Now go for the “File” button on the top.
   • Then go for “Info” and then click on “Tools.”
   • Now, tap on the “Mailbox Cleanup” option.
   • Now go to “View Mailbox Size” from the menu to check the overall size of your mailbox stored in the OST file.
   • Using this “Find” option, you can search for the older (or larger) items by entering the days (or file sizes).
   • Now, you can delete unwanted data to reduce the OST file size.
3. Compact the OST file
   Microsoft Outlook has an option to compact OST files, which lets you reduce the file size. It compacts the OST or a PST file to decrease the size. Check the following steps to compress the OST file.
   • Open Outlook, then File, and click on the Account Settings option.
   • Under the Data Files tab, select the required Outlook data file.
   • Click on Settings >> Advanced. Here, click on Outlook Data File Settings.
   • Click on the Compact Now button and hit the OK button.

   This method will compact your selected OST file and helps you to resolve the issue temporarily.

4. Modify offline settings
   Microsoft Outlook offers this helpful option to specify how offline data is to be synchronized after the availability of the server. Through this, you can control the synchronization of data. It would help if you modified through manually the “Mail to keep offline” settings.
   • Start with opening your Outlook account. Reach the “File” button and click on the “Info” option.
   • Select “Account Settings” from the info option and click again on “Account Settings.” Afterward, choose the option of “Change.”
   • On the “Mail to keep offline slider,” you can adjust the settings of the OST file size. Then adjust the slider to the lower value to synchronize the data. This will reduce the OST file size.

In a Nutshell

Sometimes, Outlook users face the ‘OST File has Reached the Maximum Size’ error. Due to this error, you cannot store more information and data on their OST files. Above, we have discussed the methods to fix this issue. If the above solutions fail, try Recoveryfix for OST to PST Converter. It is a straightforward tool to handle all OST file issues and quickly converts inaccessible OST files to PST. Even non-technical persons can easily use it. It is used for all versions of Windows.