Hello, im in need of some help. The company i work for has 2 different domains. Im using general terms here but lets say that the 2 domains are company1 and company 2, but they are part of 1 big company, business wise. For company 1, the net admin has a W2k3 Domain Controller with OUs and objects specific to their company. On my end, which is company 2, i have a Win2008 Domain environment. The Exchange Server 2007 that is here on my end needs to host mailboxes and route mail for both of our companies. I have my domain and my users already connecting to their exchange mailboxes, but i cant Company 1 to connect at all. We have a VPN tunnel setup to allow traffic from Company 1's 2k3 Domain Controller and our 2008 DomainController only, but it feels as though this is not enough. What am i missing ?Any help would be greatly appeciated as I have searched all over the web for this and still havent gotten a good source...And another thing, the trust has been set up both ways for the domains but one of my problems is that i cant resolve the names and users from the other domain, and the other way around....

Do you have2 domains in 1 AD forest or do you have 2 AD forests with each 1 domain?If you have 2 AD forests then you can readhttp://www.msexchange.org/articles_tutorials/exchange-server-2007/planning-architecture/deploying-exchange-resource-forest-part1.htmlIs your VPN tunnel configured to only allow DCs to talk to each other or are clients in company 1able totalk to servers of company 2?

Please try to nslookup the domain 1s DC from domain 2, and vice versa. So we can confirm if the DNS and forest trust have been set up properly J-H has provided a good article for deploying the exchange 2007 in a resource scenario, heres another good article that may help

Ok.. i was able to nslookup from my 2008 Server but when i tried to nslookup my 2008 Server from the Server 2003, it wouldnt work. I just keep getting the external IP address of Company1.In regards to your question J-H... im not sure how the AD is setup. But to me it looks as though each is in its own forest. How can i confirm that ? And also, the VPN tunnel is configured to only allow the DCs to talk to eachother... no client conversations are taking place.*UPDATE* After some checking around, i can confirm that this is a 2 Forest Configuration and that the exchange server is part of my Server 08 Forest. We dont have the hardware/software/cash to put Exchange on its own forest right now..

I am not a firewall expert.I don't think it is sufficient if only the DCs can talk to each other.The clients also have to have access to the Exchange server in company 2.I would not be surprised if the Exchange server also wants to talk to the DC in company 1.If comapny 2 has to host mailboxes for company 1 then company 1 should trust comapny 2 - this would be far less complicated.

I suggest that you shall verify the trust between forests, provide your exact procedure in the Windows Server forum and confirm if theres anything wrong on the forest trust

I have verified that the trusts are working (both incoming and outgoing) by following the instructions on this page:http://technet.microsoft.com/en-us/library/cc753821.aspxIm just wondering if its because we are running a 2008 Server here on our end and our Domain Functional Level is set at 2008, while the other end is running on Server 2003 with a functional level of 2003. Would this have anything to do with my issues ?

I have a test computer set up on the other site and the funny thing is im able to resolve IP addresses and was able to ping my exchange server thru the tunnel.So i created a new mailbox for auser called "Test" on my Exchange Server.Then using RDPto connect to my test machine on the other site,launched outlook to configure the mailbox, but i keep getting a logon prompt and no matter what username and password combination i put (even tried the local admin account), it wont let me log on.Keep in mind that the other company is in Camarillo andis on their own domain, so they are not part of my domain here in LA.Anyone know whats goin on, this is driving me nuts..haha

Can anyone out there help me out ?