RT 4.0 will reach end of life on February 15, 2017. It is recommended that users upgrade their RT instances to a supported version, 4.2 or 4.4, before that time.
Request Tracker, with its first class support for email, offers the familiarity of a shared inbox. On top of that, RT brings the organizational power of an enterprise ticketing system.
To celebrate the release of RTIR 4.0, we recorded a video showing a typical workflow and some key features of RTIR.