Hi all, I have a temporary issue that I am hoping you can solve. I am about to put a second DC/Exchange on the same subnet. This DC and domain is no way related to the first. A company is about to split and do not have the resources to seperate the network. On the first domain, I assume I can just forward all requests that it cannot process to the secondary domain. DHCP will be running on the first domain only. With Exchange, I will have it so that if the recipient is not found in AD, route to second Exchange server. Does this make sense? Will it work? I need network users logging in to both domains, but I don't want them joined, or a trust between them. Seems fine to me, just want to make sure.

The assumption here is that you are going to have two domains (call them domainA.com and domainB.com), so you should have two different sets of MX records in the forward lookup zones for domainA.com and domainB.com (and two recipient policies generating different email addresses depending on the domain). Since the companies are splitting, then customers and partners should be notified of the new email addresses because they will likely be treating the new companies as separate entities. When mail is coming in to either domain, then it should be going to at least two different IP addresses (based on the MX records, at least one existing for each domain), so you should not need to try to forward mail that is undeliverable in the first domain to the second domain. This would also be against the current standards because the server is supposed to reject the message if it cannot be delivered, so if the first domain accepts all mail, there would not be a reliable way to generate non-delivery reports without creating a new outgoing message (whereas the non-existent recipient would generate a 5xx message, permanent failure, during the initial SMTP session with the server attempting to send the message). -- Mike Burr

Thats fine... This is only a temp solution for about a month or so. My main concern is that both ad domains can live seperatly on the same network.

They should be able to, the main issue will be ensuring that the clients are pointing to the correct DNS servers to look up the SRV records for their respective domains. -- Mike Burr

They can all point to the first domain, since it's going to be the dhcp server. Then that can use forward lookup of the second domain to point them in the right direction?

Hi, I am not sure if the Exchange can work properly. You may confirm with the Exchange experts in the Exchange forum Exchange forum http://social.technet.microsoft.com/Forums/en-US/category/exchangeserver From an AD point of view, the solution should work.This posting is provided "AS IS" with no warranties, and confers no rights. 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.