Exchange 2019 Event ID25021 and EAC inaccessible

Question

ENV

• Exchange server 2019
• Windows Server 2019

Issue
Unable to access ECP/EAC, OWA, and OLK 365 clients cant find the server via Autodiscover, but OLK 2016/2019 can both internally and externally

Existing OLK clients are connected and unaffected by the current situation, nor is email flow.

EXRCA

• EXRCA SSL test passes ok
• EXRCA OLK connectivity test fails with Testing HTTP Authentication Methods for URL https://mail.OURDOMAIN.com.au/rpc/rpcproxy.dll?mail.OURDOMAIN.com.au:6002.
  The HTTP authentication test failed. Additional Details
  A network error occurred while communicating with the remote host. Exception details: Message: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 59.154.n.nnn:443 Type: System.Net.Sockets.SocketException Stack trace: at System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress) at System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state, IAsyncResult asyncResult, Exception& exception)

Some reading suggested a problem with the SSL cert, but the SSL test from EXRCA disagrees,

The System Event log is full of Event ID 15021 Source HttpEvent with the details shown as

An error occurred while using SSL configuration for endpoint 0.0.0.0:443. The error status code is contained within the returned data.

In the friendly view of the event details it has

- Execution
[ ProcessID] 4
[ ThreadID] 29740

I can see that it is port related, I'm just not sure where to go next.

Late Addition
0800 2022-Aug-05 - OWA and ECP Pages are accessible but afterlogin details are entered displays this error
Exception Details: System.Web.HttpException: https://mail.OURDOMAIN.com.au/owa/auth/errorFE.aspx?CafeError=SSLCertificateProblem
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Answer 1

Hi @Shane King ,
According to error information , the main cause may is the SSL certificate is bound incorrectly or is not bound.
Please open Internet Information Services (IIS) Manager in Exchange Server, and have a check that the certificate binding for the default Web site and exchange back end is Microsoft Exchange.
If not , please refer to steps in the following link to reconfiguration your SSL certificate and see if it works.
Server Error in '/owa' Application Exchange Server - ALI TAJRAN

NOTE: Microsoft provides third-party contact information to help you find additional information about this topic. This contact information may change without notice. Microsoft does not guarantee the accuracy of third-party contact information.

Besides , when you install Exchange 2019 on a server, three self-signed certificates are created and installed.
Digital certificates and encryption in Exchange Server | Microsoft Learn

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Answer 2

Hi AholicLiang-MSFT,

I ended up lodging a support request with MSFT Support which saw the matter resolved. However since then all users are having to enter domain credentials when they start Outlook. A Dialogue box appears with their email address and when they enter their domain password it isn't accepted. They then have to click on More Choices and enter their domain username and password before OLK will connect to the mailbox. Any ideas as to what the Support tech would have changed to cause Exchange to require this now.