Ok so two domains with two-way domain trust. Exchange 2007 SP3 in each domain. Distriubtion Groups have "Require that All Senders are Authenticated" checked by default in both domains. What needs to be configured so that users in Domain A are "authenticated" in Domain B and can send to groups in Domain B that has that checkbox checked (and vice versa). Would it be setting up a sepcial recieve connector on Domain B that is set to only use TLS (and a corresponding Send Connector in Domain A to send to the recieve connector?). Would Mutual Auth TLS be needed? Anybody have an article that talks about this? Am I over-complicating things or way off base? Thanks much

Hi, We can setup connector between these two organization. Be note we need to select Externally Secured on the connector. More detail information you can check the article below: Configure Cross-Forest Connectors http://technet.microsoft.com/en-us/library/bb123546.aspx Xiu