I'm looking at the following articles: http://technet.microsoft.com/en-us/library/bb125224(EXCHG.80).aspx- preparing Active Directory http://technet.microsoft.com/en-us/library/aa997914(EXCHG.80).aspx- preparing Legacy Exchange Permissions It appears these should be thefirst things to dowhen installing Exchange 2007. My domain currently has one Exchange 2003 server. After completing all the steps in the above articles, will my domain still be happy with my Exchange 2003 server and will it continue to function normally? Is there anything I should be aware of before going through the described steps, i.e. is this going to break anything? Are users going to see anything different or will this be transparent to the users? Thanks in advance.

Hello Lucciano, Preparing AD & Domain for Exchange 2007 is seamless task to users and your existing Exchange 2003 servers and you can continue to use Exchange 2003 as normal. It just prepare your AD environment for Exchange 2007 to enter with its own set of attributes, required groups, configuration container and permissions.

Excellent. Thank you.