Outlook 2003:Verifying the Folder Size of Your Mailbox
You should check to see what the size of your mailbox is. To do this, you will have to be using Outlook setup on the exchange server. Instructions are below:
STEP 1: You should right click on your Mailbox and click Properties for Mailbox
STEP 2: In the Properties window, click on the Folder Size button.
STEP 3: The Folder Size window will now appear. Click the Server Data tab (not necessary unless Outlook is running in Cached Exchange Mode). The amount of space being used is indicated by the Total size (including subfolders): line. You should make note of this number and record it for reference later. This number is in KB (kilobytes) and the eRaider information will be in MB (megabytes). To convert to MB, simply divide the folder size that is in KB by 1024.
STEP 4: Now click Close and then OK to return to Outlook.