Know How to Increase Mailbox Size in Outlook 2016

Do you want to know how to increase Mailbox size in Outlook 2016? You land on the right page. The article contains various ways through which you can increase the mailbox size. So, read the article carefully.

Microsoft Outlook is a great email client with various features. If you have been using this email client software, you may have encountered a mailbox size limit. It is one of the common errors in Outlook and appears when you exceed the limit of the PST file.

The PST file size limitation varies from version to version. In Outlook 2002, the maximum file size is only 2 GB, whereas this PST file size is 50 GB in Outlook 2016. So, you can save more data in the latest versions. However, after reaching the size limit, you turn to the error of Outlook mailbox size limit exceeded.

Now, let us know how to increase mailbox size in Microsoft Outlook.

How to Increase Mailbox Size in Outlook 2016?

The manual process to increase Outlook mailbox size Office 365 is effective. It is a free way to resolve the issue, and you do not need any third-party software to repair Outlook PST. The method is efficient but suitable for professional users because the steps are slightly hard.

How Do You Increase Mailbox Size in Outlook Manually

Step 1: Press Win+R to open the Run command. Type regedit and click on the OK button.

Outlook mailbox size limit exceeded

Step 2: Now, you will see the Registry Editor on the screen. Expand the HKEY_CURRENT_USER option from the list in the left pane.

increase Outlook mailbox size Office 365

Step 3: Navigate to the following location to find the PST file.

For Single User

For Outlook 2003 users, navigate toHKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\PSTFor Outlook 2007 users, navigate toHKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\PSTFor Outlook 2010 users, navigate toHKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\PSTFor Outlook 2013 users, navigate toHKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\PSTFor Outlook 2016 users, navigate toHKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\PST

For Administrator account

For Outlook 2003 users, navigate toHKEY_CURRENT_USER\Software\Policies\Microsoft\Office\11.0\Outlook\PSTFor Outlook 2007 users, navigate toHKEY_CURRENT_USER\Software\Policies\Microsoft\Office\12.0\Outlook\PSTFor Outlook 2010 users, navigate toHKEY_CURRENT_USER\Software\Policies\Microsoft\Office\14.0\Outlook\PSTFor Outlook 2013 users, navigate toHKEY_CURRENT_USER\Software\Policies\Microsoft\Office\15.0\Outlook\PSTFor Outlook 2016 users, navigate toHKEY_CURRENT_USER\Software\Policies\Microsoft\Office\16.0\Outlook\PST

Step 4: After reaching the above location, create the following two values if they are not available.

  1. MaxlargeFileSize
  2. WarnLargeFileSize

Step 5: Right-click on the blank space and select New > DWORD (32-bit) Value. Or you can choose QWORD (64-bit) Value in case you are using a 64-bit operating system.

the Outlook data file has reached the maximum size Office 2016

Step 6: Assign the name MaxLargeFileSize to this entry.

Step 7: Again, repeat Step 5 to create a new value and name this entry as WarnLargeFileSize

How do you increase mailbox size in Outlook

Step 8: Next, assign a value to these newly created entries. Double-click on the MaxLargeFileSize.

Step 9: In the Value Size, enter the maximum size limit of the PST file in MB. It should be greater than the existing file size limit. For Outlook 2016, the size limit is 50 GB. So, you can enter 102400 for 100GB. Choose Decimal in the Base and press OK to save it.

Step 10: Now, double click the WarnLargeFileSize and enter 95% of the MaxLargeFileSize value in this value field. Again, choose the Base as Decimal and press the OK button.

Step 11: Finally, close the Registry Editor. And check the Outlook mailbox size will increase.

The above method is a manual solution to fix the mailbox storage space issue. It is an effective solution but quite complex. Also, it is not suitable when the error message arises due to PST file corruption. Therefore, the best key to increase mailbox size in Outlook 2016 is to use third-party software.

Professional Solution

Outlook PST Repair is a comprehensive solution to restore corrupted and damaged PST files. The tool can repair the complete mailbox data like Emails, Journals, Contacts, etc. After recovering, the PST repair software can save the file in various file formats. It is an ideal solution when the Outlook data file has reached the maximum size of Office 2016 due to corrupted PST files. It restores the file content and resolves the issue.


Hopefully, you find the solution for your query – How to increase mailbox size in Outlook 2016? The article has described the method to set mailbox size limits issue. However, the manual answer becomes ineffective when PST files are damaged. So, the best practice in this situation is to use the professional approach and get rid of PST & OST file too large in the Outlook issue. It restores the PST files to their normal state and resolves the issue. Thanks for visiting this blog.

About The Author:

Mithilesh Tata is an Email Migration and Data Recovery Expert. He has a keen interest in Technology & Entrepreneurship. Also, he loves cricket, music, and books.


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