Hi, we have the main domain.com and the subdomain child.domain.com. There is oen Exchange organization and the Exchange server is running in the main domain for all users. The child.domain.com is in another site of AD connected over high-bandwidth VPN, so there is no problem with the connection. I installed another Exchange server in the child.domain.com, then tried to move some mailboxes over to the server to keep them local for the users. However those users cannot receive any email internally. The can receive and send email to the Internet, and they can as well send it out to other users in the same organization. I restarted and checked Recipient policies, routing engine and smtp service. I tried also to create RGC connectors or even smtp connectors. None of them helped. The same is happening also with any new mailbox created in that subdomain. The mail sent from domain.com to chil.domain.com is piled up in the queue on the exchange in the main domain. What are requirements to let this email flow between domain.com and child.domain.com? Please let me know some your ideas if you had such experience. Tkx