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alangao-5587 avatar image
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alangao-5587 asked ZhengqiLou-MSFT commented

Outlook 2016 can't connect to exchange 2016

I recently installed 2 exchange servers and added to existing DAG. The DAG has a total of 3 servers. Now a few users can't connect to exchange. While add the profile, it failed at "Logging on to the mail server". The error Outlook can't log on. Verify you are connect to 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.

What could be the problem? Thanks.

office-exchange-server-administration
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AlexC-8264 avatar image
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AlexC-8264 answered

Have you been adding the third server to the load balancer?
Compare the results from Test-NetConnection cmdlet of one client successfully connecting to the server name to the result of the failing client.
You can take the accessed server name by Ctrl+rightclick the outlook icon in the tray, selecting Connection Status.
Please use the event viewer anf filter for source "Outlook" to check for further information about wanrings or errors.

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ZhengqiLou-MSFT avatar image
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ZhengqiLou-MSFT answered ZhengqiLou-MSFT commented

Hi @alangao-5587 ,

Are the problematic users from the new-installed servers? Or do they have some common attributes?

As I know, joining the DAG will not affect the using for Exchange server and Outlook client. So I think it should be the servers itself.
You could use the Test-OutlookConnectivity cmdlet to find if there are any messages:

 Test-OutlookConnectivity "Outlook.Protocol\OutlookRpcDeepTestProbe\MDB1" -RunFromServerId Exchange2016 -MailboxId test@contoso.com | FL

Replace MDB1,Ex2016 and test@contoso.com to the users'.
Or you can test it by EXRCA: https://testconnectivity.microsoft.com/tests/Ola/input

Also please try the following methods:
1. Create a new mailbox from the new servers, or migrate the old, problematic users to other mailboxes/servers.
2. Check the certificates, make sure it's using the right ones for both frontend and backend.
3. Try logging in to OWA with these users.

Best regards,
Lou


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I tried several ways and it is the new added server having issue. If I set DNS to this new exchange server, then outlook can't connect. I tried OWA access and directly connect to this server, it still doesn't work. Is it virtual directory that caused it? I have right certificate and copied VD URLs from other servers... I am puzzled ...what could be wrong?

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Hi @alangao-5587 ,

Hum, forgave my stupid question: what do you mean "set DNS to this new exchange server"? Because as I know, the on-prem Exchange server's DNS should be using the Domain Controller's IP address.

Also please run the cmdlet Test-OutlookConnectivity I give above, that may provide us some useful error messages.

Do you mean the OWA is good to access or it also failed? If you could login to OWA while not Outlook client, I think that's an Autodiscover problem.

The certificates, please check you're using the same certificate( whatever it's default self-signed or provided by a business CA/your own domain CA) in IIS for frontend and backend.

Best regards,
Lou

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And the VD URLS should point to the new server's URL.
Like
https://ex3.contoso.com/ecp
https://ex3.contoso.com/mapi
etc..

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