I will have 2 CAS/HT Servers (hardware load balanced) and for now one MB server, will do DAG in the future. I am wondering about the version of Exchange 2010. I want to maintain the most flexibility (in terms of using Exchange Enterprise CALS for journaling, custom retention policies, etc) but reduce the cost as much as possible. I am thinking that I can go Exchange 2010 Standard for the two CAS/HT Servers and Exchange 2010 Enteprise on the Mailbox Server and be able to still use Enterprise CALs and all features in the future. We will start out with Standard CALs. Would this work? I know you can mix Exchange versions, I am hoping that the two CAS/HT dont need enterpise versions of Exchange in this case.

Enterprise edition of Exchange is unrelated to the CALs. There are no feature differences - the only reason for using Enterprise edition of Exchange is to get the increased number of databases (50). Basically unless you have a very large number of users (1000s) you wouldn't need Enterprise edition of Exchange at all. However you will need to use Enterprise edition of WINDOWS on the mailbox servers to do the DAG. Standard edition of Windows will be fine for everything else. Therefore if you are likely to use a DAG, put the mailbox server/s on to Enterprise edition of Windows as you can't upgrade it later. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.

Hi eChange, Some information for you: http://www.microsoft.com/exchange/en-us/licensing-exchange-server-email.aspx http://www.microsoft.com/licensing/about-licensing/client-access-license.aspx Regards! GavinPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.