I am performing an upgrade of exch 5.5 to exch 2003 and have upgraded some servers to win2003 OS in the same domain. I now plan to install the AD connector on this win2003 server (to be new exch 2003) and install the first exch2003 server into existing 5.5 site. Can you tell me what is the best practices for installing this first exch server. ie should it be a DC. should i have different mirror sets for system and transaction logs / exch databases etc? Once migration has completed to exch 2003 am i ok to rename the exch 2003 server to the same host name as old exch 5.5 server (once it is decommisioned and off the network) to save reconfiguring all the client outlook profiles?