Error: Source error - No valid EWS URI has been provided.

Error:

While running the credential check Platforms step, error: "Source error - No valid EWS URI has been provided." is displayed.

Cause:

EWS on source or destination hosted Exchange server is not properly configured.

Resolution:

In Site Bindings part of the IIS, all host names need to be removed.

Open IIS console, select the your website (it may be the Default Web Site), right click on it and select option Edit Bindings...

In Site Bindings Window, remove entries which contain any value for Host Name so it would be empty

One other thing that also needs to be checked is the EWS URL. This can be done via PowerShell on the Exchange server:

Get-WebServicesVirtualDirectory | fl InternalUrl, ExternalUrl

Result should be:

InternalUrl : https://yourdomain.com/ews/exchange.asmx
ExternalUrl : https://yourdomain.com/ews/exchange.asmx

If the result is something else, you can set it up to point to proper URL:

Set-WebServicesVirtualDirectory -InternalUrl https://yourdomain.com/ews/exchange.asmx -ExternalUrl https://yourdomain.com/ews/exchange.asmx