Hello All, I have deployed a multi domain environment and would like to know how to federate these domains together. In total i have 4 domains...lets say they are; domain1.com domain2.com domain3.com domain4.com There is an exchange server in domain1.com that i would like to open mailboxes on from any of the other domains. I need to know; A = What is required B = Are there any technet articles explaining how to do this C = What implications may this have on my setup I have looked into ADFS and it seems to be only related to single sign on and not federation services. I would also love to be able to log into the domain1.com domain from any of the other domains as well! Thanks in advance, Daniel

Build two-way trust between domain 1 and other domains, and run the domainprep on other domains. Please try the scenario on the virtual enviroment at first