Handling the General e-Mail in an Organization?

cheezycrust asks: "I'm part of a small organisation (four staff members, seven board members), and we get a lot of mail on our info@... email-address. Some of the questions are complex, and require input from several staff and/or board members. I'm looking for a way to track and handle these messages. It seems to be a combination of a bug tracking and a groupware system. It should be very simple to use, be platform-friendly (Windows, Mac, Pocket PC), and work on- and off-line (if I want to handle 50 messages on a train ride, this should be possible). I have a preference for free software, but the administration of the software itself should not take too much time. What solutions have you used in your organisation?"