Is it possible to have a Single OWA website to serve all Exchange Sites? If I have users whose mailboxes are stored in Site2, they can't access their mailbox using the OWA located at Site1... Do I need to have one OWA for each exchange site? Thanks in advance, Thiago Bujnowski

You can use one OWA website to serve all sites. I'm assuming you're on 2003 and not using a front end which is why it's not able to proxy. Please describe your Exchange versions and your topology setup.James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

Oh.. Sorry.. I'm using Exchange 2010 SP1 I have 2 Exchange Sites in diferent Cities. But Site2 does not have it's own internet connection. It has a private line connecting it to Site1 and then, to the internet. I currently have two proxy rules using two diferent external addresses. One pointing to the CAS at Site1 and one pointing to the CAS at Site2. Users whose mailbox are stored on Site2 can't access the OWA on Site1. Upon trying to log in they are redirected to OWA on Site2 and then they have to input their credentials again. I don't like the idea of having multiple OWA URLs. Is there anyway to have a single OWA to access all of the mailboxes stored in any exchange site? Thanks in Advance, Thiago Bujnowski

On Site1 there's a CAS, MAILBOX, HUB and EDGE On Site2 there's a CAS, MAILBOX and a HUB

The proxying should've worked by default. Can you see if the ExternalURL was set on the site2s cas server? It should be blank. In the Exchange Management Console, click Server Configuration, and then click Client Access. In the work pane, select the Client Access server being proxied to, and then select the /owa virtual directory. Click the Outlook Web Access tab. Right-click the /owa virtual directory, and then click Properties. In the virtual directory properties dialog box, click the General tab. James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

When I left it blank, people on Site2 couldn't not access any OWA at all. I got an error message saying that it couldn't be access from that location. I'll try to reproduce the error to provide an accurate error message.

Hi Thiago, Please use get-owavirtualdirectory on the cas server in each site, and then post the information here, we could do more research regarding to your issue. Some information for you: http://technet.microsoft.com/en-us/library/bb310763.aspx Regards! Gavin Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Ok. I got the error now. Just as James suggested, I left the OWA External URL blank at Site 2. When I try to log on the OWA at Site 1 using credentials from a user whose mailbox is located at Site 2, I get the following error: Outlook Web App isn't available. If the problem continues, please contact your helpdesk But it works normally if I use credentials from a user located at Site 1. Here are the results of the command: [PS] C:\Windows\system32>get-owavirtualdirectory Name Server OwaVersion ---- ------ ---------- owa (Default Web Site) CAS-RJ01 (SITE1) Exchange2010 owa (Default Web Site) CAS-SP01 (SITE2) Exchange2010 I've done some modifications on IIS at Site 1 to redirect HTTP to HTTPS. But Site 2 have the default settings. If I type http://mail.contoso.com it redirects me to https://mail.contoso.com/owa https://mail.contoso.com also redirects me to https://mail.contoso.com/owa

I'm getting the following error on CAS at Site 1: Level: Error Event ID: 41 Task Category: Proxy The Client Access server "https://mail.contoso.com.br/owa" attempted to proxy Outlook Web App traffic for mailbox "/o=Contoso/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=Name Lastname". This failed because no Client Access server with an Outlook Web App virtual directory configured for Kerberos authentication could be found in the Active Directory site of the mailbox. The simplest way to configure an Outlook Web App virtual directory for Kerberos authentication is to set it to use Integrated Windows authentication by using the Set-OwaVirtualDirectory cmdlet in the Exchange Management Shell, or by using the Exchange Management Console. If you already have a Client Access server deployed in the target Active Directory site with an Outlook Web App virtual directory configured for Kerberos authentication, the proxying Client Access server may not be finding that target Client Access server because it does not have an internalUrl parameter configured. You can configure the internalUrl parameter for the Outlook Web App virtual directory on the Client Access server in the target Active Directory site by using the Set-OwaVirtualDirectory cmdlet. I can see connections going from Site 1 to Site 2 https port. So I'm guessing it has found the internal URL but it's not being able to authenticate. I tried setting Site 2 to Integrated Windows Authentication but I keep getting the same error...

You set integrated authentication but did you also remove FBA authenication? If not you need to remove FBA on second site CAS.James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

I had left only Integrated Authentication checked. But the problem persisted. I got it working now after I forced AD Replication to Site 2! So, Changing the authentication to Integrated Authentication solved the problem Thank You Very Much for the support!

If you're in Exchange 2007, you need to have CAS and Hub in every site where you have a Mailbox server.