Using Outlook/Exchange for Customer email

We receive around 200 emails a day from Customers to our Customer Service Center. I am looking into the possibility of replacing an old email management system (Mustang)with something that can utilize our existing Excahnge 2000/Outlook 2003 apps.

Our needs are fairly basic and don’t need the bloated/expensive Enterprise versions that are being touted.
Is anyone actively using a system based on Exchange 2000 that they could recommend?

Thanks,

Alan