Hi All,

We had recently upgraded our Exchange Server 2007 to Exchange 2013 Standard. We have decommissioned the old exchange server after all the mailbox and role transfer.

Within the internal network we are unable to configure the Outlook using the FQDN of the Exchange server, upon entering the server name we are getting the follwing error:

With Cached Mode Enabled:

This action cannot be completed. The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action.

With Cached Mode Disabled:

Outlook cannot log on. Verify you are connected to the network and are using proper server and mailbox name. The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action.

A peculiar thing to note is however, without any proxy configuration the Outlook does resolve to the exchange server when we enter the Primary Domain Controller - FQDN/ IP address but as mentioned it does not resolve this even if we enter the actual Exchange server FQDN, however once this is done and we open Outlook we get the following error:

Cannot start Microsoft Outlook. Cannot open the Outlook window. The set of folders cannot be opened. You must connect to Microsoft Exchange with the current profile before you can synchronize your folders with your Outlook data file (.ost)

Because of which we are unable to connect our Internal clients to the Exchange, this has been tested on Outlook 2013, 2010 on both Workgroup and Domain machines. However from Outlook mail config once we enter the proxy configuration from More Settings -> Connection -> Connect to Microsoft using HTTP -> Exchange proxy settings and as we enter the External server details Outlook will resolve the server name and we can connect to Exchange.

Any help or assistance with the above issue is much appreciated. Thanks in advance.

Hello

check internal and external url settings, dns and on client trusted the exchange cetificate.

Download the "Microsoft Connectivity Analyzer Tool" on testexchangeconnectivity.com. It's located on the "Client" tab. This allows you to run the same tests that the testexchangeconnectivity.com sites does, but from your internal network.

If everything is working for external clients, then what you're describing sounds like either your internal URL's aren't correct or the authentication settings you have configured for your internal clients doesn't match what is configured on your CAS servers.  Where it gets confusing is that you have authentication settings for both internal and external clients as well as authentication settings on the actual IIS virtual directories.

Hi Corey,

Many thanks for your answer. 

Could you please let me know how we can verify if the authentication settings for internal client and CAS are the same?

Hope the following helps, this is the output of the Get-OutlookAnywhere power-shell command:

Identity                           : EXCHSRVR\Rpc (Default Web Site)
ExternalClientAuthenticationMethod : Negotiate
InternalClientAuthenticationMethod : Negotiate
IISAuthenticationMethods           : {Basic, Ntlm, Negotiate}

Thanks,

Hi,

For your question, please ensure Exchange server configure correctly with below checklist, it also helpful for further troubleshooting:
1. Run Get-ClientAccessServer | FL Identity,*Uri* to check the setting for SCP.
2. Run Get-OutlookAnywhere | FL Identity,*hostname*,*Auth*,*SSL* to check the host name and authentication for Outlook anywhere.
3. Run Get-MailboxDatabase | FL Identity,*Rpc* to check the setting for RpcClientAccessServer.
4. Run Get-OutlookProvider | FL Name,Server,*CertP* to check the setting for CertPrincipalName.

Moreover, auto-configure Outlook account to check whether all settings are same with Exchange server.

Thanks