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How to view mailbox or folders' sizes in Outlook?

Author Kelly Last modified

Has your Microsoft Outlook become heavy and working slowly? There may be a number of email messages, tasks, and appointments congesting Microsoft Outlook for a long time. Before cleaning up your mailbox, you'd better check how much space folders take up currently. Here we will show you how to check and view each mailbox or folder’s sizes in Microsoft Outlook quickly.

View mailbox or folders' sizes with the Properties feature

View mailbox or folders' sizes with the Mailbox Cleanup feature


View mailbox or folders' sizes with the Properties feature

You can check the space that the mailbox and its folders occupy currently in the folder properties. Please do it with the following steps:

Step 1: Right-click the root folder of a mailbox, and click the "Data File Properties" in the right-clicking menu.

screenshot about how to view mailbox sizes in Outlook 1

If you are using Outlook 2007, you will get the "Properties for 'Personal Folders'" instead of "Data File Properties" from the right-clicking menu.

Step 2: In the Folder Properties dialog box, please click the "Folder Size" button.

screenshot about how to view mailbox sizes in Outlook 2

Then in the Folder Size dialog box, you can easily check the mailbox size and the sizes of each subfolder. See the following screenshot:

screenshot about how to view mailbox sizes in Outlook 3

Note: For a single folder without subfolders, you can’t view the size of it by this method.


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View mailbox or folders' sizes with the Mailbox Cleanup feature

When you are cleaning up your mailbox, the "View Mailbox Size" feature enables you to view the total size of the current mailbox and the sizes of each folder in this mailbox.

Step 1: Open the Mailbox Cleanup dialog box:

  • In Outlook 2010 / 2013, please click "File" > "Info" > "Cleanup Tools" > "Mailbox Cleanup". See the following screenshot.
  • In Outlook 2007, please click "Tools" > "Mailbox Cleanup".
screenshot about how to view mailbox sizes in Outlook 4

Step 2: In the Mailbox Cleanup dialog box, please click the "View Mailbox Size" button.

screenshot about how to view mailbox sizes in Outlook 5

Then in the coming Folder Size dialog box, you can view the total size of this mailbox, as well as the sizes of each subfolder in this mailbox, including the Inbox folder, Sent Items folder, Outbox folder, Deleted Items folder, etc. See the following screenshot:

screenshot about how to view mailbox sizes in Outlook 6

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