I'm about to implement an Exchange 2007 Server. On the client side, I have about 150 users and understand that I need an Exchange CAL for each. I also have "resources" such as conference rooms and company cars for which I create calendars on the Exchange server. My understanding is that I don't require a CAL for resources, only for users or devices. Problem is that with in my current environment with Exchange Server 2000 and Windows Server 2003, the License Manager on Server 2003 allocates a license for each user AND for each resource. Am I required to obtain Exchange CALs for the resources that I create calendars for? If not, how do I keep License Server from allocating an Exchange CAL for my resources?

Talk to your reseller, but you either need 1. CAL per device that accesses exchange (smart phone, laptop, desktop, etc) 2. CAL per actual user, generally resource and service account mailboxes don't count, but again, talk to you reseller to be 100% sure. I don't think anyone, including microsoft takes license manager seriously....doesn't everyone just crank it up all the way and use SMS to report? :-)

If you are going to use Windows 2008, don't worry about license mananger at all since I don't think it exists anymore. And unless you are using SBS, just disable it on the Exchange servers. http://support.microsoft.com/kb/824196

if you have 100 users but they all share one computer (and dont use OWA or anything else) then you would only need 1 device cal. if you had 100 computers, but only 10 users you would want to buy 10 user cals. thats it. they dont need to overlap, but cant change after you bought them. microsoft licensing usually answers pretty quick when you call: https://licensing.microsoft.com/eLicense/L1033/Overview.asp

BTW, Exchange 2010 makes this question easier to answer, as it displays the CAL requirements when EMC 2010 is opened.

Exchange Server 2007 Licensing Licensing ModesExchange Server is licensed in the Server / Client Access License (CAL) model. Under this model, an Exchange Server license is required for each operating system environment running Exchange Server. A CAL is required for each user or device accessing Exchange Server. Server and Client Access License EditionsExchange Server 2007 is offered in two server editions: Standard Edition Enterprise Edition Exchange Server 2007 is also offered in two CAL editions: Standard CAL Enterprise CAL Either version of the CAL may be run against either version of the server. To learn more about the server and CAL editions, see Exchange Server 2007 Editions and Client Access Licenses. The Exchange Server Standard and Exchange Server Enterprise CAL licenses are also included in the Enterprise CAL Suite. Note: The External Connector license (EC) is an optional additional server license for external users that enables access to your servers running Exchange Server 2007. With this license, you do not need to buy individual Exchange Server CALs. The EC license is purchased for every copy of Exchange Server 2007 that can be accessed by the external user. An example of an external user is a person who is not an employee or similar personnel of the company or its affiliates. This license allows access to the Exchange server by an unlimited number of external users that can include, but is not limited to, business partners, suppliers, customers, retirees, and alumni. It is licensed per server. Upgrading Exchange Server 2007 Evaluation Software to Exchange Server 2007 Standard Edition or Enterprise EditionYou can upgrade your server running Exchange Server 2007 evaluation software to Exchange Server 2007 Standard Edition or Enterprise Edition at the end of the 120 day evaluation period with your product key. For more information about obtaining a product key, see Volume License and Online Services Keys. For more information about upgrading Exchange Server 2007 evaluation software, see Enter Product Key Wizard > Enter Product Key Page. More on this check the below Linkhttp://www.microsoft.com/exchange/2007/howtobuy/default.mspxAs friends suggested the best option is to call your reseller or Microsoft....