I hope I am aksing this question in the correct forum. We run Exchange 2003 as part of SBS 2003. We have outgrown the Exchange limitations within SBS and have purchased a new server which will be a dedicated Exchange 2010 server. My question is, can I run them both in parallel whilst I move mailboxes? Thanks

Yes, a migration from both Exchange 2003 and Exchange 2007 to Exchange 2010 will be supported. As shown in the article Transitioning to Exchange 2010, you can see that Excahnge 2003 is supported. "You can only transition to Exchange 2010 from the following existing messaging systems: Exchange 2007 messaging system Combined Exchange 2003 and Exchange 2007 messaging system This means that if you are upgrading from an Exchange 2003 or Exchange 2007 organization, you can choose to either transition the organization, or migrate to a new organization. In most cases, you will want to retain the Exchange data from the existing organization, and so you should choose to transition to Exchange 2010. If you are upgrading from any messaging system besides Exchange 2003 or Exchange 2000, your only option is to migrate to Exchange 2007." Coexisting with Exchange 2010 http://technet.microsoft.com/en-us/library/aa998604(EXCHG.140).aspx Ripu Daman Mina | MCSE 2003 & MCSA Messaging

Hi, And more information about migrate Exchange 2003 to Exchange 2010. Exchange 2010 Deployment Assistant http://technet.microsoft.com/en-us/library/ee681665.aspx Exchange 2003 - Planning Roadmap for Upgrade and Coexistence http://technet.microsoft.com/en-us/library/aa998186.aspx Rapid transition guide from Exchange 2003 to Exchange 2010 http://msexchangegeek.com/2010/01/30/rapid-transition-guide-from-exchange-2003-to-exchange-2010/ Frank Wang

Thank you for help, those articles should give me all the information I need.

yea i believe you can have 2 exchange servers in the same orginization....thats how i did, i had 03 running, and my new 10 running simotanously in same org....then moved mailboxes a few at a time. Steven J Einhorn