Increase Outlook Mailbox Size to Get More Storage Space

increase Outlook mailbox sizeSince how long have you been using Outlook client? Have you ever confronted the PST file size limitation issue? I’m sure you have! There’s everything great about Outlook client, be its features or performance. But one thing that really irritates me is “Outlook mailbox size limit”. Due to a certain PST file size limit, we can only store Outlook mailbox content of a specific size. We’ll discuss Outlook mailbox size limit later in this post. Also, I’ll show you how to increase Outlook mailbox size in order to get more storage space.

Microsoft Outlook – Popular Email Client

Outlook client is widely popular not just because it’s an email client provided by Microsoft. In fact, it’s more than that. It works as a personal information manager provided by Microsoft. Microsoft Outlook client contains various features such as emails, calendar, contact management, task management, note taking, journal creation, and web browsing. It creates an Outlook data file that stores the entire mailbox content which includes email, attachments, contacts, calendars, tasks, notes, journals, etc. The Outlook data file is called PST aka personal storage table.

The PST file created by Outlook has a default maximum size limitation depending on the Outlook version. In the older versions, i.e. 2002 or earlier, Outlook uses ANSI format to save PST file. In the new versions, i.e. 2003 and later including the latest 2016, Outlook uses Unicode format to save PST file. There’s a major difference between ANSI PST file and Unicode PST file. An ANSI PST file has a maximum 2 GB size limitation. This means it just can’t store more than 2 GB of mailbox content. If we talk about Unicode PST file, it has maximum 20 GB to 50 GB size limitation. It provides you more storage space than ANSI PST file.

PST file size limit as per the Outlook version

Microsoft Outlook version PST File Size Limit
MS Outlook 2000 and earlier versions ANSI PST format – 2 GB size limitation
MS Outlook 2003, 2007 & 2010 Unicode PST format – 20 GB size limitation
MS Outlook 2013 & the latest 2016 Unicode PST format – 50 GB size limitation

Why should we increase Outlook mailbox size?

In these days, most of the Outlook users are using the latest versions, i.e. 2003 or later. Some old organizations or home users might be using Outlook 2002 or any older version. If you’re using any latest version of Outlook that uses Unicode PST file format, you’ve come to the right place. Though a Unicode PST file gives you enough storage space, sometimes it’s not enough for some Outlook users. There’s a need to increase Outlook mailbox size for those Outlook users who receive a large number of emails every day.

Do you know that a PST file is prone to corruption due to its size limitation? How? Just think you’re using Outlook 2010 which has a maximum 20 GB PST file size limit. Generally, 20 GB storage space looks enough. You receive thousands of email messages each and every day which include heavy attachments. Other than this, you create notes, tasks, journals, etc. All these items are stored in your PST file. One day you notice that the PST file is about to reach its maximum size. This might be very harmful, I’m telling you!

Outlook users might also be interested in 

Split PST File into Multiple Parts – Try Few Easy Manual Tricks

Smart Way to Remove Outlook Duplicates with Ease

Whenever a PST file reaches its maximum size, it creates serious troubles for Outlook users.

  • Now no more mailbox content can be stored in your PST file. You have to create a new PST file for storing more content. Having multiple PST files may cause Outlook management issues.
  • Due to a large-sized PST file, you’ll experience a poor performance of Outlook client. It starts hanging more often or crashing frequently.
  • The worst impact is Outlook mailbox corruption. I’ve already mentioned that PST file is prone to corruption due to its size limitation.

Increase Outlook Mailbox Size – It’s Easy

To increase Outlook mailbox size in Outlook 2003, Outlook 2007, Outlook 2010, Outlook 2013 and Outlook 2016, follow these simple steps:

Open Registry Editor

First of all, open Registry Editor. How?

Open Run command (Win+R), enter “regedit” in the search box and hit enter.

run regedit.exe

  • On Windows XP, press Win button and choose Run.
  • On Windows Vista & 7, press Win button and click the search bar (below in the list).
  • And on Windows 8, right-click on the bottom left corner of the desktop screen and select Run.

Modify Outlook Mailbox Size Limit through Registry Editor

Step 1: On the Registry Editor window, you can see a tree-structured list under Computer in the left pane.

how to use Registry editor?

Click HKEY_CURRENT_USER in the list and expand it. You need to navigate to the following registry path according to your Outlook version:

For single users
HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\PST for Outlook 2003
HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\PST for Outlook 2007
HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\PST for Outlook 2010
HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\PST for Outlook 2013
HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\PST for Outlook 2016
For administrators
HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\11.0\Outlook\PST for Outlook 2003
HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\12.0\Outlook\PST for Outlook 2007
HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\14.0\Outlook\PST for Outlook 2010
HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\15.0\Outlook\PST for Outlook 2013
HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\16.0\Outlook\PST for Outlook 2016

Step 2: Click PST in the options in the tree-structure.

how to use Registry editor?

Note: If you can’t see the PST key under Outlook key, create it manually. To do that:

  • Right-click on the blank space, and select New > Key in the options. Give it a name.

how to use Registry editor?

  • Now double-click at PST key, and find these two values in the right pane:
  1. MaxLargeFileSize
  2. WarnLargeFileSize

Note: If you can’t see these values in the registry, create them manually.

For MaXLargeFileSize
  • Right-click on the blank space, and select New > QWORD (64-bit) Value in the options. Or if you’re using 32-bit Outlook, select DWORD (32-bit) Value.

how to use Registry editor?

  • Give it a name: MaxLargeFileSize.

how to use Registry editor?

For WarnLargeFileSize
  • Again, right-click on the blank space, and select New > QWORD (64-bit) Value in the options. Note: If you’re using 32-bit Outlook, select DWORD (32-bit) Value.

how to use Registry editor?

  • Give it a name: WarnLargeFileSize.

how to use Registry editor?

Step 3: Now double-click MaxLargeFileSize value in the list.

how to use Registry editor?

Now define the value data (in MB) and its base. For e.g.

  • If you’re using Outlook 2003, 2007 or 2010, the default PST file size limit is 20 GB. Make sure you specify a size over 20 GB.
  • Or if you’re using Outlook 2013 or 2016, the default PST file size limit is 50 GB. Make sure you specify a size over 50 GB.

how to use Registry editor?

Note: Since I’m using Outlook 2010, I’ve specified 30 GB (30720 MB) as maximum large file size. You can specify the size as per your Outlook version. If you’re using Outlook 2013 or 2016, you can specify 70 GB (71680 MB) or 100 GB (102400 MB).

Then, choose Decimal in base options. Finally, click OK.

Step 4: Then double-click WarnLargeFileSize value in the list.

how to use Registry editor?

Now again define the value data (in MB) and its base. For e.g. you can specify 90% of 30720 MB, which is 27648 MB.

how to use Registry editor?

Then, choose Decimal in base options. Finally, click OK.

Now close the Registry Editor.

For older Outlook versions

Remember the above trick of “increase Outlook mailbox size” can only be used with Unicode PST file. You can’t use it for ANSI PST files. If you’re using any older Outlook version that supports ANSI PST format, you should definitely try a professional PST Upgrade software. It can successfully upgrade Outlook PST files from ANSI format to Unicode PST file format. If you don’t want to use any such professional software, you can simply upgrade Outlook by switching from an older version to any latest version.