My orginazation is looking to deploy UM and currently have Exhcange and Windows 2003 in Native mode.what are the minimum requirements to have UM up and running without going in to fully installing Exchange 2007.What servers would have to be in place or upgraded in order to accomplish this. I need to get the VOIP and Fax in UM.ThanksHarish

Hi Harish, To use Unified Messaging functionality of Exchange 2007, you need other Exchange 2007 server roles too in same AD site where you put UM server and Exchange 2003 can not interoperate with UM and Exchange 2003 Mailbox can not be UM-Enabled (further reference is in below links).It is suggested to install & configure Unifed Messaging environment with help of UM expert. Reference: Unified Messaging server role Requirement You must deploy an Exchange2007 Hub Transport server in the same ActiveDirectorysite as the Unified Messaging server role. ExchangeServer2003computers cannot interoperate with the Unified Messaging server role. Exchange2003mailboxes cannot be Unified Messagingenabled. Further detail --> Coexisting with Exchange Server 2003 and Exchange 2000 Server http://technet.microsoft.com/en-us/library/aa998604(EXCHG.80).aspx You can not do in-place upgrade of Exchange 2003 server because Exchange 2007 requires 64bit hardware and OS to run in production so you need to deploy additional server.

Dear customer: Thanks for Amits reply. Yes, of course. You are unable only install UM role without other role. For more information about Unified Messaging, please refer to the following article: White Paper: Unified Messaging Technical Overview http://technet.microsoft.com/fr-fr/library/bb738119(EXCHG.80).aspx Deploying Unified Messaging with Exchange Server 2007 http://technet.microsoft.com/en-us/magazine/cc137737.aspx Unified Messaging Architecture http://technet.microsoft.com/en-us/library/bb232168(EXCHG.80).aspx Hope it helps. Rock Wang - MSFT

Thanks Amit,This helps a lot.Harish