Error: There is no Microsoft Exchange Client Access server that has the necessary configuration in the Active Directory site where the mailbox is stored." Scenario: Central Site: AD Site 1 1-HUB & CAS facing the internet 1-Mailbox Secondary Site: AD Site 2 HUB &CAS 1-Mailbox SCR I am facing problems for the users in the Mailbox of secondary sites. Central site users are able to access their OWA properly When a user from the secondary sites tries to access the CAS in the Central site they get the above error. Another Question: If the Hub server in the secondary site is down, will the mailboxes in the secondary site (AD Site 2) use the HUB in the main site (AD Site1)? How can we accomplish this?

Hi,The internal utl on the CAS server in the secondary site must be configured properly and integrated authentication must be configured on that CAS server:http://technet.microsoft.com/en-us/library/bb310763.aspxAnswer to your second question is no. You need another HUB transport server to get fault tolerance.Leif

Hi,From the error message, it seems that the Windows Integrated authentication was not configured on the CAS in the Central site.http://msexchangeteam.com/archive/2007/09/10/446957.aspxThanksAllen