Hello - I just started at the this company and they currently have an Exchange 2007 server running and fully functional. The problem is right now they have a simple install where all components are loaded on a single server. This company is heavily regulated and the regulators have requested that the exchange server roles be separated out across multiple servers. I'm not sure of the best way to attack this project and minimize the email flow down time. I am only dealing with 125 or so mailboxes.Has anyone done this or have an instruction set for doing so? Matt

Hi,If existing server is capable to handle mailbox server role for your long-term goal then easiest way is to install two other server, install Hub & CAS on these respective and remove both roles from existing server so you don't have to move mailbox and users don't face any downtime.You need to follow steps starting from 3 in below article in this case...How to Remove the First Exchange 2007 Server in a Coexistence Scenariohttp://technet.microsoft.com/en-us/library/bb310767.aspxBut if you are planning to implement high availability clustering solution for your Mailbox server role then you need to install two other server for cluster and move mailboxes and which requires downtime for mailbox move once your CCR/SCC mailbox servers ready.Reference:How to uninstall Exchange Server 2007 and individual server roleshttp://searchexchange.techtarget.com/generic/0,295582,sid43_gci1281195,00.htmlAmit Tank | MVP - Exchange | MCITP:EMA MCSA:M | http://ExchangeShare.WordPress.com