I have a question related to unity and ms exchange design
we have planned to setup a Unity 4.2 server with failover at our customer premises.
As the need for an additional server for configuring MS Exchange was not discussed during the initial days,now the custonmer wanted to know the following
* to install Unity and Exchange in both primary and failover server[ie to keep one server's ms exchange service disabled and make it active when needed]
*if the exchange server is to be installed on the third server, wat has to be its specification to support about 300 VM users.
* is there any seperate license required to install MS Exchage in the third server.
* Wat is the specification of the servers if I had to go for MS Exchange as a cluster.
Note : Unity 4.2 with 300 VM users and MS Exchange 2003 is used.MCS 7815 I2 servers are used for Unity.