Company A just purchased company B which is a competitor right now. We are planning to integrate the 2 business down the line, but right now they need to be seperate. Company A runs on and exchange setup in house, company B runs on a hosted exchange provider. We want to move them in house. I have 2 options. Option one is build a new exchange server and put them on that. But this company is pretty small (12 people). Or Options two put them on the existing exchange server. If i put them on the existing exchange server I will need Company A to not be able to see company B in any way and vice versa. i.e. Global Address book. I will also need company be emails to go in and out a different IP address then Company A. What would you say is my best bet in this scenario and why? Thanks BenBen T Sealey

It's Exchange 2007 on a single server.Ben T Sealey

You could do Address list segregation.Check out this link: http://telnetport25.wordpress.com/2008/06/04/exchange-2007-service-pack1-and-address-list-segregation-part-1-getting-started/andhttp://technet.microsoft.com/en-us/library/bb936719.aspxSF - MCITP:EMA, MCTS: MOSS 2007, OCS 2007, Exchange 2007

I think it would be the combination of option one and two. You can introduce another exchange 2007 server with mailbox and hub server role installed into current exchange organization, and then move users mailboxes onto it. As mailbox server will prefer the hub on the same machine to send the messages, you can accomplish the separate routing And about the separate GAL, Scott has provided the link

You just need a single Exchange Server to host a number of domains. This is how many Mail Service Providers provide Mail Service to different Oranizations. You have said that down the line you are going to integrate with the second company, but for the time being they are seperate. If the first comany's domain is mycompany.com and the second company domain is othercompany.com. You can run these two domains on a single exchange server. You can view the other Comapny's GAL using Address List Segregation. Later you can merge their mailboxes into your domain itself with very less hiccup. You need not buy and maintain Two different Exchnage Servers. Hope this resolves your issue.

Well need some more info:How does company B access mail from their hosted Exchange server (POP3/IMAp4/Exchange)Comming to the question, since your primary requirement is that CompanyB mails must be routed through a seperate IP and Their GAL must not be visible in Company A GAL. So added to my friends suggestion's i have 2 Suggestions1 SuggestionIf Comapny A is having any perimeter level devices which routes mails to External, write policies on those devices stating Company A mails must go through this IP out and Company B mails must be routed through this IP.Create Mailboxes on the same Exchange 2007 Server and follow the article which was proposed by Scott.2 SuggestionAs Scott suggested, install a second Exchange 2007 server (Mailbox/HUB and CAS)in the same exchange 2007 orgnization of Company A and Map a new static IP (*.*.*.*)to that server. Create a new host name (webmail.companyB.com) and associate the new IP (*.*.*.*) which is mapped to that server. (Changes must be done on the Public DNS server of Company B.Create a MX record for the newely created Host name and create a PTR record for that public IP (*.*.*.*)If these records are existing on the Public DNS server of Company B change the IP associated to those Host names with your Public IP (*.*.*.*)Create Mailboxes on the same Exchange 2007 Server and follow the article which was proposed by Scott.This procedure will fullfill your both requirements

This is just my own opinion, of course. I hate to do something twice.Go with option3 and leave them hosted until you are ready to merge them in to your existing organization. There is no point in disrupting Company B's users merely so you can bring them in house, but run them separately. Do it one time when the companies are ready to formally merge. If you are attempting toobfuscate the fact that Company A now owns a competitor, you are certainlydefeatingthat goal by virtue of assuming control of Company B's IT infrastructure. Jim McBee - Blog - http://mostlyexchange.blogspot.com