Macintosh ( Networking & Email )

In our Office we are exclusively NT 4.0 / Windows 2000 with a few ’98 workstations dotted around and oh yes – the one obligatory Mac for one of the web designers. it is a G4 and I would like to have it connected such that the user can receive email from our exchange servers on the mac instead of him having an NT workstation that he uses just for internal email. The mac works fine with the assigned IP address, Internet connectivity is OK. What do I need to do in order to get exchange email on the MAC ?