IT Organizations should feel in charge and have an overview of the incidents that occur. Incidents and questions from users should be handled in one central place. To make life easier you can use the OTRS Helpdesk. OTRS is completely open source (you pay no licensing) and can be easily adapted to your specific needs or desires.
Industrial TSI offers a helpdesk OTRS system that with the addition of ITSM modules make a full ITIL Incident Management system ( OTRS ITSM ).