The .exe file that you have will not work on your eMac. The Mac version of Propel is a separate download. Also, the site does not have any current information on Mac web browsers. For example - Internet Explorer is now considered to be obsolete on the Mac, even by Microsoft. Safari is now at version 3, and other web browsers commonly used on Macs, such as Firefox and Camino, are hardly mentioned at all.
Not very good Mac support, I'm afraid - especially for a service for which you pay monthly...