How can I fix Outlook 2010 not connecting to Exchange 2013 after SSL certificate renewal? OWA/ECP inaccessible by policy.

Question

Environment:

• Exchange Server 2013 CU23
• Windows Server 2012 R2
• Client: Outlook 2010 on Windows 7
• Important Note: OWA and ECP are not accessible by design, so the issue must be resolved through Outlook client configuration.

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Problem:

After the previous SSL certificate expired, I installed a new DigiCert certificate on the Exchange server and rebound it in IIS for HTTPS. Since then, users are unable to connect using Outlook 2010.

Outlook prompts with the following message when launching or creating a new profile:

"Outlook cannot log on. Verify you are connected to the network and are using the proper server and mailbox name. The connection to Microsoft Exchange is unavailable."

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Troubleshooting Already Performed:

• Installed and bound the new SSL certificate for IIS, SMTP, IMAP, and POP via Enable-ExchangeCertificate -Services "IIS,SMTP,IMAP,POP".
• Verified that the Autodiscover DNS entry points to the correct IP of the Exchange server.
• Confirmed port 443 is open and bound to the correct certificate.
• Clients trust the DigiCert root and intermediate certificates.
• Checked that TLS 1.2 is enabled via registry on both client and server.
• Ran Test-OutlookConnectivity -ProbeIdentity "OutlookRpcSelfTestProbe" and it fails with RPC or encryption-related errors.
• Verified mail flow is functional (internal and outbound mail is processing).
• Receive connector on Exchange is listening on port 587 with TLS required.

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Event Viewer Logs:

• Event ID 12014 (MSExchangeFrontEndTransport): Exchange cannot find a certificate containing the expected FQDN and cannot support the STARTTLS SMTP verb.
• Event ID 1310 and 1309 (ASP.NET): Configuration errors mentioning certificate or assembly load failures.
• Outlook 0x800CCC0E errors on the client when attempting manual IMAP configuration.

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Current Roadblock:

Although all bindings appear correct and certificate trust is in place, Outlook 2010 continues to fail to connect, and no profiles can be created or opened. This behavior began immediately after the certificate renewal.

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Request:

Given that OWA and ECP are not usable, and mail flow is confirmed functional, what specific steps should I take to restore Outlook 2010 connectivity with the current Exchange 2013 setup?

Any help identifying overlooked configuration areas or additional diagnostic steps would be appreciated.

Answer 1

Hi @Malik2025 ,

Outlook 2010 is sensitive to SSL and Autodiscover issues. If the new certificate’s name doesn’t match the server settings (like Autodiscover or Outlook Anywhere), or if it's not fully trusted, Outlook fails to connect. Also, older Outlook and Windows versions may not handle TLS 1.2 correctly without extra setup.

Double-check that the certificate includes all needed names and that Outlook Anywhere and Autodiscover are using those names. Try creating a new Outlook profile. If the issue continues, consider enabling OWA/ECP temporarily for deeper testing, then turn them off again if needed.

You can check this blog to fix the connection issues.

Please Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.

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