I am planning on these major steps for a COEXISTENCE scenario : 1- JUST adding TWO Exchange 2010 SP! servers (One with the CAS/HUB roles the other with the Mailbox role) to an Exchange 2007 SP2 production environment DURING office hours. 2- START making changes AFTER office hours QUESTION: Would step 1 cause any disruption in the Exchange 2007 server regarding mail flow, connectivity and other services? I just want to save time and JUST add those servers during office hours Thanks John

Hi No, that's fine! Have you used Exchange deployment assistant? If not, it can help you with checklists etc http://technet.microsoft.com/en-en/exdeploy2010/default%28en-us%29.aspx Jonas Andersson MCTS: Microsoft Exchange Server 2007/2010 | MCITP: EMA 2007/2010 | MCSE/MCSA Blog: http://www.testlabs.se/blog

Thanks Jonas for your reply. I just want to make sure no disruption is caused and take advantage of those hours. I feel safer about doing it. Thanks for that link. John

No problem, just don't change anything about the mailbox, certificates etc. Plan it well, then you're home :) Just post if anything is unclear Maybe this post can help you? http://www.simple-talk.com/sysadmin/exchange/upgrade-from-exchange-2007-to-exchange-2010---part-1/Jonas Andersson MCTS: Microsoft Exchange Server 2007/2010 | MCITP: EMA 2007/2010 | MCSE/MCSA Blog: http://www.testlabs.se/blog