How to Increase Outlook Mailbox Size

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With the Microsoft Outlook program, which is the most popular email client among PC users, you can create your own mailboxes and archive files to store your email messages. Outlook sets limits on the size of these mailboxes, but they can be adjusted by editing your system's registry. In order to increase the size of your Outlook mailbox, you must have administrative privileges on your computer.


Things You'll Need

  • PC running Windows XP or later
  • Microsoft Outlook 2003 or later

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Step 1

Log on to your PC computer with an administrative account.


Step 2

Open the Start menu and click "Run."

Step 3

Type "regedit" into the text field and hit "OK" to launch the Registry Editor.

Step 4

Use the database tree on the left side of the window to navigate to the HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\11.0\Outlook directory.


Step 5

Open the "Edit" menu at the top of the window and choose "Key" from the "New" subfolder.


Step 6

Type "PST" and hit the "Enter" key to name the new value you are creating.


Step 7

Go back to the "Edit" menu and select "New DWORD Value" from the list of options.

Step 8

Label the new value "MaxFileSize" and then enter the amount of space you want your Outlook mailboxes to be.



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