Answers:
1. It is recommended and I second the motion, not to install Exchange 2003 on a DC though it can be done. This is a decision you'll really have to think about (This will get you started - http://www.microsoft.com/technet/prodtechnol/exchange/Analyzer/7423376e-686b-4cda-b90f-cf5cff4f8981.mspx). It's best to run Exchange on it's own server.
If you are running Exchange Server 2003 on a domain controller, using the domain controller promotion tool (DCPromo) to change the computer role is not supported, and it is known to break components such as Microsoft Outlook? Mobile Access (<- an issue listed below).
If you are running Exchange Server on a domain controller without Small Business Server, consider the following issues:
? Exchange Server and Active Directory are both resource-intensive applications. There are performance implications to be considered when both applications are running on the same computer.
? If Exchange Server is running on a domain controller, you must also make that domain controller a global catalog server.
? Several Exchange Server directory components, such as Directory Service Access (DSAccess), Directory Service Proxy (DSProxy), and the Message Categorizer will not fail over to any other domain controller or global catalog server.
? You should not take advantage of the /3GB startup switch in Windows because it could cause Exchange Server to consume all memory, therefore reducing the memory available for Active Directory.
? System shutdown will take considerably longer if the Exchange Server services are not stopped before shutting down or restarting the server.
? This configuration is less secure because Exchange administrators will have local administrative access to Active Directory, enabling them to elevate their own privileges. Additionally, any security vulnerability found in either Exchange Server or Active Directory exposes the other to compromise.
? If you are running Exchange Server 2003 on a domain controll
