Light weight RT alternative?

I’m a huge RT fan and I use it to handle low volume email coming into a
support@ email address. Unfortunately I’m moving hosting for the
organization that uses it to a virtual environment and I do not have access
to httpd.conf or the pre-req’s to run RT.

Does anyone know of anything that would offer similar features and be
virtual host friendly? php based or perl is fine, but I need to be able to
share tickets with a team of responders who should be able to respond to
those tickets via email.

RT does everything I want but its requirements are preventing me from
running it in the limited resources of shared hosting.