Moving Exchange 5.5 to another server

Exchange 5.5 is currently installed on an NT4 server which will need to be scraped soon and I would like to setup Exchange 5.5 on a new Windows 2000 server. I have setup Exchange 5.5 on the W2K server by joining the existing site – so I think it is reading information (all the mailboxes) of the NT4 server? If the NT4 server went down, would the W2K server still keep Exchange up and running with all normal settings/mailboxes/information? If not, how can I transfer the information/mailboxes over to the W2K server? I have Arcserve 2000 backup software on the network — can this be put to use here?