In most of the cases the process to remove a certificate for any reason that we may have is a straight forward process in Exchange Server 2013 and we won’t notice a thing besides of a pop-up if the remaining certificate is not valid for the end-users but the service will be available.
However, in some cases when the certificate is removed improperly then the administrator/users may have an issue to access all web interfaces on the affected server.
The process to remove a certificate is simple, using Exchange Admin Center (EAC), click on servers and then certificates. Select the certificate that you want to remove (in our case the Public one, named Apatricio.info – Public Certificate) and hit the third icon from the left (trash icon).
A dialog box will require confirmation, just click on OK and we should be fine. Another certificate will take over IIS (responsible for OWA/ECP/WebServices and so forth).
What happen when something goes South?
In some scenarios, where the certificate is removed without the proper methods the administrator may get the following error message when trying to access the server itself (https://servername) and the same applies for /owa and /ecp.
If we have a second Exchange Server in the organization we can check the certificates on the affected server, and we will notice that the default Microsoft Exchange (or any other certificate that you may have assigned) has the IIS which means that certificate should be the one being used by IIS and the page should be working by now.
However, in some cases the binding is lost and we have the error that we noticed at the beginning of this section. A possible solution is to check the Bindings… of the Default Web Site
In the new window, select https 443 and click on Edit
Probably, if you are experience the issue of this Tutorial you will have Not Selected under SSL Certificate.
Click on it and change to the certificate that is on Exchange Admin Center (EAC) that has IIS assigned to it, in our case Microsoft Exchange and click OK.
Let’s reset the IIS to refresh all settings by running the following command on a PowerShell/Command session as administrator.
Time to go back and try to connect on OWA or ECP and this time the result will be what we are expecting, as shown in the figure below.
In this Tutorial we went over the process to troubleshoot a certificate issue when the certificate is not removed properly.