Hi All, I have an Exchange 2007 Organization with around 10000 mail boxes. Due to a business decision the company will be split into separate business identities and will operate as different companies. Based on this decision the below are few key points Two new companies will be formed Company A and Company B Off the current 10,000 users Company A will retain 8000 users and Company B 2000 users Mail access, Active Sync and blackberry are the key exchange services used The current SMTP id is <user name>@company.com The above SMTP address will be retained for the users of Company B ( New Company of 2000 users) The Current messaging platform will be retained by Company A ( New Company of 8000 users) and Company B will migrate out Company A will get new SMTP domain address as <user name>@companyA.com Please suggest the best approach to have this transition implemented and the risks involved . Also please suggest the probable issues that we might have to manage during and post this transition Regards, RangRanga

Best approach? Hire a consultant. There are too many factors involved to list them there, and I am certainly not listing them here for free. Simon. Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.

Best approach? Hire a consultant. There are too many factors involved to list them there, and I am certainly not listing them here for free. Simon. Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.

Hi, For Exchange part, we need to do cross-forest migration. You can create new emial address policy for <user name>@companyA.com first. And then set company.com as the primary email address. Create new domain environment and establish forest trust to do account and mailbox migration. How to Transition from Single Forest to Cross-Forest http://technet.microsoft.com/en-us/library/aa996926(v=exchg.80).aspx Exchange 2007 Cross Org Mailbox Migration http://blogs.technet.com/b/exchange/archive/2006/11/02/3396084.aspxXiu Zhang TechNet Community Support

Hi, For Exchange part, we need to do cross-forest migration. You can create new emial address policy for <user name>@companyA.com first. And then set company.com as the primary email address. Create new domain environment and establish forest trust to do account and mailbox migration. How to Transition from Single Forest to Cross-Forest http://technet.microsoft.com/en-us/library/aa996926(v=exchg.80).aspx Exchange 2007 Cross Org Mailbox Migration http://blogs.technet.com/b/exchange/archive/2006/11/02/3396084.aspxXiu Zhang TechNet Community Support

Do cross forest migration to split one of the company's off. The main thing is you need to support a period of coexistence because say you migrate off company B to the new forest. I doubt you will be moving thousands of mailboxes over a weekend. Therefore when you start migrating some company B users, they will need visibility to other company B users or perhaps even A users. 1. ADMT with cross forest mailbox moves for company B. There is an order of moves, for example move AD security groups first. Then move Exchange DL's last. 2. Set up cross forest Free Busy coexistence 3. Set up Galsynchronization (galsync with contacts needs to exist for cross forest free busy to work) 4. Provision new BES server in new forest, use transporter suite to mgirate company B's BES accounts If you have any specific questions post back. James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

Do cross forest migration to split one of the company's off. The main thing is you need to support a period of coexistence because say you migrate off company B to the new forest. I doubt you will be moving thousands of mailboxes over a weekend. Therefore when you start migrating some company B users, they will need visibility to other company B users or perhaps even A users. 1. ADMT with cross forest mailbox moves for company B. There is an order of moves, for example move AD security groups first. Then move Exchange DL's last. 2. Set up cross forest Free Busy coexistence 3. Set up Galsynchronization (galsync with contacts needs to exist for cross forest free busy to work) 4. Provision new BES server in new forest, use transporter suite to mgirate company B's BES accounts If you have any specific questions post back. James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com