Implement support ticketing system connected to Exchange+SQL

For our customer service department we are looking for a solution to streamline customer support using a ticket system. This system can be open-source or not and run on either Windows or Linux. The developer can discuss his choice of software It should contain the following features: - automatically assign incoming e-mail messages a ticket number - ability to assign priorities, categories and due dates - assign issues to particuler customers (from CRM database) - reminders for overdue items - ability to communicate with Microsoft Exchange (used for e-mail) - communication with CRM database, in Microsoft SQL (or any other ODBC data source) - storage of tickets in ODBC-compatible database Available server platforms: - Microsoft Server 2008 with SQL 2008 and Exchange 2007 - MacOSX Server 10.6 Please make a proposal for this scenario. Other details: - milestone upon starting, release when total working solution is available - communication through IM - three weeks to complete