Greetings, Hi guys, I know that in order for Exchange 5.5 (win 2k OS) to work with Exchange 2000, I have to installed ADC. Is it possible for both of them to work together without installing ADC at Exchange 5.5. Appreciate any advice. Thanks Alan Tan System Consultant Nomura Research Institute 6 Battery Road #36-01 Singapore 049909 (o) +65 6420 1946 (f) +65 6420 1989 (m) 96710270