All, I have a client which are using hosting email server with specific domain (example ; contoso.com) Building internal AD and internal Exchange Server with domain : bankgroove.com, and i also created UPN Suffices "contoso.com" So each user in the internal domain can login to their computer or to their OWA using username@contoso.com eventhough the real internal domain is bankgroove.com Currently i have configure the Exchange Server 2010 on the Hub & Transport, New accepted domain which is "contoso.com" with External Relay. I have also build a Send Connector which point to the SMTP of the ISP. The i tried to simulate the email delivery : 1. Sending email to other use that have email in the hosting server of contoso.com (result : OK) 2. Sending email to other domain of contoso.com such as Gmail, Yahoo, Hotmail (result : OK) The problems occurs if : I create a user in AD (example : user logon : michael@contoso.com, domain : bankgroove.com) without mailbox in internal Exchange Server, but this user has email mailbox in the hosted email server with email address : michael@contoso.com). I can't send any email to michael@contoso.com from internal Exchange User, the message that appears in Exchange Server is "Last Error: The mailbox recipient does not have a mailbox database" because it tries to look first in the Internal Exchange Server first. Are there any way, so the Exchange Server can skip checking all the mailboxes in the Exchange Server ? Or can Exchange send all the email to the External Relay eventhough for local mailbox users ? Best Regards, Ben

hello, create a contact in your internal exchange as: michael@contoso.comIbrahim Al Masry http://www.ibra.me/

hope this helps http://technet.microsoft.com/en-us/library/aa998858.aspx Adnan