If you are receiving errors about being close to your quota for your Exchange e-mail account, follow the instructions given to attempt to decrease the amount of e-mail saved to your online account in an attempt to avoid reaching your quota.
Open Microsoft Outlook. Click the Tools menu at the top of the the window and then click the Mailbox Cleanup... menu option.
The Mailbox Cleanup window will pop-up. Click the View Mailbox Size... button.
The Folder Size window will pop-up. From here, you can see the size of each folder on your hard drive. Click the Server Data tab.
The Server Data tab contains information about the size of folders on the Exchange server. From here, you can see the size of each folder to see how close you are to your quota limit. Click the Close button when finished.