I'm at a point where I have retired both 2000 DC's with a 2003 DC and raised the forest to a 2003 level. There is still an Exchange 2000 server in the environment. From what I understand neither exchange version 2000 and 2010 will know of one another if introduced. So since I want to have a fresh exchange environment I believe I could just install exchange 2010 onto the domain. I will then create all mailboxes from scratch.... Except, what then happens in A.D??? Can I do what I want to? Or must I move to a 2003 Exchange environment to then move to a 2010 exchange environment just for the purposes of Active Directory? Point is I don’t care about using Microsoft to move the mailboxes. I would rather re-create all mailboxes and start from scratch. But at the same time, I need to keep the exchange 2000 environment in production until the exchange 2010 server is ready to go live. And yes this all will be on the same domain… Thanks B

You can't upgrade an existing Exchange 2000 organization directly to Exchange 2010. You must first upgrade the Exchange 2000 organization to either an Exchange 2003 or Exchange 2007 organization, and then you can upgrade the Exchange 2003 or Exchange 2007 organization to Exchange 2010. We recommend that you upgrade your organization from Exchange 2000 to Exchange 2003, and then upgrade from Exchange 2003 to Exchange 2010. http://technet.microsoft.com/en-us/library/aa996959(EXCHG.65).aspx http://technet.microsoft.com/en-us/library/aa998604.aspx Your already have an live exch Org 2000 in the forest so it's not possible to deploy exch 2010 in the same Forest/domain.Sukh

Agree with Sukh, you can't migrate from 2000 to 2010 directly.Gulab | MCITP: Exchange 2010-2007 | Skype: Gulab.Mallah | Blog: www.ExchangeRanger.Blogspot.com

Hi, Microsoft doesn’t support to migrate from Exchange 2000 to Exchange 2010 SP1 directly. There is an idea: setup a temporary Exchange 2003 server as intermediate. Migrate from the 2000 users to 2003, then over to 2010. Once everyone is on the 2003 server, decommission the 2000 box. Repeat this for 2010. For domain and forest functional level, you can use Windows server 2003 domain functional level and Windows server 2003 forest functional level, which can be supported by Exchange 2000 SP3, Exchange 2003 SP2 and Exchange 2010 SP1. There are some articles as following: Exchange Server Supportability Matrix Step-by-Step: Migrating Exchange 2000 to Exchange 2003 Using New Hardware Migrating from Exchange 2003 to 2010 Hope this helps. Thanks Please 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.