Hello, We have recently installed Exchange 2007 with OWA feature. All the mailboxes are moved to the new server. Our Exchange 2003 also is still running in the environment. After making this new exchange server active, whenever a user opens outlook in his machine login profile, the window for login details keep popping. Once the user gives in the login credentials, it again pops up after sometime. I figure it is some OWA certification error. Can anyone help me in resolving this issue. It is creating lot of issues for all the users. Thanks, Amit

Hi Amit, First, please understand you should replace all your Exchange 2003 Front-end servers with Exchange 2007 CAS server before moving all mailboxes to Exchange 2007. We don't support putting an Exchange 2003 FE server in front of an Exchange 2007 Mailbox server. At the same time, please let me know the following questions: How Outlook connect to Exchange? RPC over Http or TCP/IP? What were you doing when the authentication window pop up again? E.g. Youre visiting a public folder or something else. I figure it is some OWA certification error ----------Whats the symptom? Please also let us know if there is some related error in event log. Thanks, Elvis

Hello Elvis, We don't have frontend servers in our network. We are using only MAPI, OWAand RPCoverHTTP protocol to connect to Exchange 2003. In Exchange 2007, we have put CAS, Hub Transport and Mailbox role on a single server. Here also onlyMAPI, OWAand RPCoverHTTP protocols are enabled. We will be decommissioning our Exchange 2003 server soon.When we open outlook after loging to the domain with thelogin id, it prompts for authentication. It happens for allTCP/IP and RPCoverHTTP clients. I have noticed one thing, that if I give the url of OWA and FQDN of the exchange server in the bypass proxy setting of the IE then I don't get this login page. But I guess in the normal environment we don't need to bypass the proxy right.How can I check what can be the OWA certificate error.Please let me know.Thanks,Amit

Hi,Im on the same scenario. Any update on this? Is there a way how to bypass proxy?or what to configure on the proxy server side, im using Trend Micro proxy server.ThanksLRMCP

Amit,The certificate error can be due to 3 issues1. Certificate Name Mismatch (i.e. the name of the certificate/SAN entries is not the same as that of the OWA URL)2. Validity (Certificate might be expired)3. Not Trusted (The root certificate might not be in the trusted root container. For a selfsigned install the same cert in the root container)In IE when you access OWA, you can click on certificate error > View certificate and check which one of these stand true for youGenerally, proxy is needed when you are trying to access a resourse which is outside your network.But you can anytime remove the proxy and try to access the OWA URL, with the netbios/fqdn of the exchange server and then check.Harpreet Singh Khandiyal (http://support.microsoft.com/kb/555375)

Which is the default DNS and the alternate DNS on the clients?Try to change the Primary DNS to the local GC, and then flushdns - registerdns., Check if you are able to locally able to access the OWA page.Also check if you are able to ping the local exchange server with IP, netbios and fqdnHarpreet Singh Khandiyal (http://support.microsoft.com/kb/555375)

I had a similar issue and it was because the OWA virtual directory for each Client Access Server did not match with the certificate attached to the Client Access Server. I used the following article to resolve the issue: http://www.shudnow.net/2007/08/10/outlook-2007-certificate-error/ Basically, I ran these commands: Enable-ExchangeCertificate -services IMAP, POP, IIS -Thumbprint "Thumbprint" Set-ClientAccessServer -Identity "ServerName" -AutoDiscoverServiceInternalUri https://DomainName.com/Autodiscover/Autodiscover.xml Set-ActiveSyncVirtualDirectory -Identity "ServerName\Microsoft-Server-ActiveSync (Default Web Site)" -InternalURL https://DomainName.com/Microsoft-Server-ActivesyncBrian Kirby