How to tell if you have Exchange 2003 Enterprise or Standard

1) Application Log – Use the event viewer on the Exchange server and analyze the Application Log.  If event id 1216 is reported when the Information Store comes online then you have Standard.  If 1217 is reported then you have enterprise.

2) System Manager – In Exchange System Manager, tree down to the “Servers” folder  and click the folder itself so your servers appear in the right pane.  This view should show 2 columns including an “Edition” column.  This was originally found here where this a screenshot.