A lesser known thing cropped up the other day, and I thought it worth sharing. The question is which IP addresses go in the ExchangeServers.txt file which is used with owauser.wsf on the EV server. The answer is :-
* Each Exchange 2007 that has the CAS role.
* Each Exchange 2003 or Exchange 2000 back-end server.
There is no need to put in the Exchange 2003 / 2000 Front-End server in there.