Hi, I am currently working in the planning phase of an IT standarization project and have the following situation: (1) The "company" has 2 AD-MS domains: OLD ("old.local") and NEW ("new.corp") and hence 2 MS-XCH 2007 (same name: OLD and NEW) organizations (each for domain) (2) Company needs to garantee that the (escalated: site by site) user migration (from OLD to NEW) does not have e-mail coexistence problems (3) Today the company receives e-mail through the "company.com" Internet (DNS) domain and needs to keep receiving mails in this way during and after the migration process (4) I plan to register a new Internet domain, called "new.company.com" and asociate it to the "NEW" MS-XCH organization By reading in detailhttp://technet.microsoft.com/en-us/library/bb124423.aspx, I'd like to be sure that the internal relay domain configuration there suggested runs on this particular situation, by using an ETS on the OLD organization for accepting both Internet domains ("company.com" as Authoritative and "new.company.com" as Internal-Relay), creating SEND connectors and usingMS Identity Lifecycle Manager 2007 FP1 for contact replication. Could you please explain me in detail which other technical aspects do I need to take care in order to satisfy the company's mentioned requirements? Is my proposed plan the correct solution for the situation? Thanks in advance for yor comments and suggestions, ///Gonzalo Gonzalo ROMERO MS IT Consultant

I think you can go without creating new domain and keeping same company.com domain shared between old and new exchange organization, refer below article and let us know if you have any doubt... How to Configure Exchange 2007 to Route Messages for a Shared Address Space http://technet.microsoft.com/en-us/library/bb676395.aspxAmit Tank | MVP Exchange Server | MCITP: EMA | MCSA: M | http://ExchangeShare.WordPress.com