Hello, I currently have a single forest single domain AD infrastructure holing Exchange Server 2010 with DAG and DAC enabled. Now the company acquired a new company and we need to join it to our forest. Deploying a replica server at the new company is out of the question since they have almost everything hosted with a third party so I have to go with a child domain. The question here is can I deploy exchange in the child domain to be hosted at the new company with DAG? Will the users of the new domain appear in the Address Book of the current users and vice versa? Thank you.

Hi MadRam, I am little confused about your issue. Do you mean, you want to deploy a DAG member server in the new company, and want to let the new company's user address book which hosted by third party could appear in your own exchange 2010 email system and vice versa? In my opinion, it is difficult to achieve and confirm, that means depend on what email system was used by the new company. If they use also use hosted exchange 2010, we could use federation. If I misunderstand your issue, please tell us. Regards! Gavin TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com 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.

Dear Gavin, Sorry that my question wasn't clear. to keep it simple I got an Exchange 2010 in the parent domain called Domain.com. I am planning to deploy a child domain called Child.Domain.com and need to deploy Exchange 2010 in this child domain. Is this scenario feasible or not? Best Regards,

Hi This can be accomplished Read through this http://technet.microsoft.com/en-us/library/bb125224.aspx Jonas Andersson | Microsoft Community Contributor Award 2011 | MCITP: EMA 2007/2010 | Blog: http://www.testlabs.se/blog | Follow me on twitter: jonand82