How To FIX Outlook Data File PST Has Reached the Maximum Size Error

In Microsoft Outlook, users can save their email attachments and folders as offline files. The.pst file extension designates Outlook Data Files. It’s simple to move these documents from one system to another. However, there is a size limit for.pst files, and if you try to increase it, Outlook will give you an error message stating that your data file is too large. Please check this whole article thoroughly to know how to fix this issue.

Maximum size is reached In Outlook For Windows 11 10

If you encounter an error saying that Outlook has reached its maximum size, then follow the below-given steps to fix it:

1. A .pst file size reduction.

2. Modify the limit of the .pst file’s size using the Registry Editor

Method.1 Reduction in the size of a .pst file

Ste.1 On your system, please Launch the Microsoft Outlook application.

Step.2 Locate the “File” tab and click on it.

Step.3 Proceed by selecting “Account Settings” from the File menu. Again choose the “Account Settings” located in the dropdown menu.

Step.4: click the “Data Files” tab in the Account Settings window. You will find a list of files associated with your Outlook account.

Step.5 Locate the particular .pst file and select it for which you want to reduce the size.

Step.6 Click the “Settings” button above the file list.

Step.7 In the Settings window, navigate to the “Advanced” tab.

Step.8 Under the Advanced tab, click “Outlook Data File Settings.”

Step.9 A new window will appear. Proceed by clicking on the “Compact Now” button.

Step.10 Please permit a few minutes for the process to finish for the reduction of the .pst file size.

Step.11 Click “OK” to close the window once the process is finished.

Method.2 Modify the limit of the .pst file’s size using the Registry Editor.

Step.1 Access the Run dialog box; use the keyboard shortcut Win+R.

Step.2 Within the Run dialog box, input the command REGEDIT and press Enter to launch the Registry Editor window.

Step.3 Navigate to the following path in Registry Editor:


Step.4 Right-click on any space in the right pane.

Step.5 Select the “New” option and then choose “DWORD (32-bit).” It will create a new entry of type DWORD (32-bit).

Step.6 Rename the newly created entry as “MaxLargeFileSize.”

Step.7 Double-click on the newly created option”MaxLargeFileSize” entry to open its properties.

Step.8 In the properties window, locate the “Value Data” field and change its value to 102400.

Step.9 Click on the “OK” button to save the modification you have done.

Following the above steps, you will successfully establish a maximum file size of 100GB for the .pst file.

Step.10 Create another DWORD (32-bit) entry and rename it “WarnLargeFileSize.”

Step.11 Double-click on the “WarnLargeFileSize” entry to open its properties.

Step.12. In the properties window, locate the “Value Data” field and modify it to 97280.

Step.13 Click “OK” to save the modification you have done.

By configuring the “WarnLargeFileSize” entry with a value of 97280, you will receive a warning when the .pst file size exceeds 95GB. Previously, the notice would trigger at 47.5GB.

A reboot is required to put changes into effect. So, reboot your system after following the above step.

If your PST file size surpasses 100GB, you have several options. First, you can increase the size limit for .pst files to its maximum and then compress it. If the issue persists, you must follow the remaining opportunity to fragment the .pst file into smaller parts.


By implementing the solutions and workarounds outlined in this article, you can effectively resolve the error related to the Outlook data file reaching its maximum size. Following the two options of increasing or decreasing the PST file size, you can over counter this issue. Reducing the PST file size is highly recommended because increasing it may corrupt or damage your file. Moreover, it can also result in performance issues with Outlook running in Windows 11.


You Might Also Like