Mailbox Cleanup

Keeping Your Mailbox Below the Size Limit

Mailbox sizes are limited:

Students (who are not forwarding) = 100 MB

Faculty/staff = 275 MB

To keep your mailbox below the limit, there are a few things you can do. These recommendations assume you are using Outlook to check your email. If you only use Outlook Web Access, just make sure to delete items from your Inbox, Sent Items, and Deleted Items often and regularly.

For more information, including videos, visit the Training Team's Managing Your Mailbox tutorial page.

Permanently delete items

When you delete an email, it goes into your Deleted Items folder. You can bypass the Deleted Items folder:

  1. Select the email. To select multiple emails, hold down Ctrl or Shift.
  2. Press Shift & Delete together.
  3. When prompted, select Yes to permanently delete the item.

Save the email but delete the attachment

Want to free up space on the server but don’t want to delete or move the email? Try deleting the attachment!

  1. Double click on the email to open it.
  2. Right-click on the attachment and select Remove.
  3. Close the email.
  4. Select Yes to the question “Do you want to save changes to this email?”

Better yet, don't send attachments through email. Instead, students can take advantage Webspace, and faculty/staff can use their Webspace, departmental server space, or SharePoint site, depending on their department's setup.

Mailbox Cleanup

  1. Go to the Tools menu and select Mailbox Cleanup.
  2. Click the View Mailbox Size... button
  3. You may see tabs for Local data and Server data. If so, go to the Server data tab.*
  4. Look at the Total Size. This is the size of your mailbox in KB. Roughly 1,000 KB = 1 MB. You can see which folders are problem areas by scrolling through the subfolder list. Usually problem areas include Deleted Items, Inbox, and Sent Items.
  5. Start deleting items from the problem folders.
  • Local data is the size of your local .ost file, the file Outlook creates to store local information for when you don't have an Internet connection as well as any settings you've changed. Local data size is generally unimportant; only server data is affected by your mailbox limit.

You can also use Mailbox Cleanup to search for files older than a specified age or greater than a specified size. This helps you pinpoint emails to delete or move to personal folders. Mailbox Cleanup also allows you to AutoArchive immediately and Empty your Deleted Items folder, both of which will reduce the size of your Exchange mailbox.


Offline Personal Folders

Personal Folders are folders that you create on your hard drive to store email messages. Personal Folders have a .pst extension. You can manually move emails from your Exchange mailbox to a personal folder, or create a rule to automatically move certain messages for you.

Personal Folders can be stored anywhere on your hard drive, but can only be viewed using Outlook. Note: If you ever upgrade computers, you will want to transfer this file to your new computer - so make sure you know where you put it! You also want to be able to Backup this file along with your other important documents.

Personal Folders are a great way to manage the size of your mailbox. You can move email from your Exchange mailbox to your own computer so that your mailbox on the server remains smaller than the designated 100 MB (students) or 200 MB (faculty/staff) of space.

For more information go to Outlook Personal Folders.

To create a Personal Folder:

  1. Select File > New > Outlook Data File
  2. Click OK
  3. A window will appear asking where you would like to save your Personal Folder. Put it somewhere you will be able to find it, like My Documents.
  4. Next, give your Personal Folder the name that will appear in Outlook. Click OK.
  5. Your Personal Folder will appear in the Folder List.

Because offline personal folder files are saved on your personal computer, you can allow them to get very large and not worry about filling your Exchange mailbox. However, since that email now only resides on a particular computer, if you are using a different computer or are using Outlook Web Access, you cannot see emails saved in your pst file.


AutoArchiving is a built-in feature in Outlook that automatically moves files from your Exchange server to a personal folder file on your computer. It allows you to save older emails without hogging space in your Exchange mailbox. An archive folder is just an offline personal folder that automatically moves email based on date.

AutoArchive is a two-step process:

Step 1 - How often do I want to archive?

  1. Select Tools > Options > Other tab.
    To begin the configuration process, click the AutoArchive button.
  2. You can check how often you want to run AutoArchive. We recommend that you also check to Prompt before AutoArchive runs. If you accidentally shut down your computer while Archiving is occurring, you can lose emails. Prompting before archiving will ensure this won't happen.

Step 2 - How old are the items you archive?

You can set all folders to a default setting or give each folder individual settings.

To set the default settings:

  1. You set the default archive settings in the same AutoArchive screen as above. Set the Archive to clean out items older than any number of months, weeks, or days.
  2. You can tell Outlook where you want these items to be saved. Note: If you get a new computer, you will want to transfer this file to it - so make sure you know where you put it! If you have already set up an offline personal folder, you can select to archive to that same file.
  3. Click Apply these settings to all folders now to set all mailbox folders to the default settings.

To set an individual folder's archive settings:

  1. Select the folder in the Folder List. Right-click and select Properties. Select the AutoArchive tab.
  2. Select Archive this folder using these settings.
  3. Set the Archive to clean out items older than to any number of months, weeks, or days.
  4. Set the Archive to Move old items to default archive folder.
  5. Click Apply and OK to save your changes.
    NOTE: We recommend setting the Calendar to never archive.

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