For one of our application in Mule on-prem, we are using a self-signed certificate to achieve HTTPS and port 443. When we are hitting from postman or soapUI we are able to get the response back.
However, our client configured this API in one of their system and from that system when they trigger the url it is giving "SSL handshake error: Received fatal alert: certificate_unknown" error.
What could be causing this error which we don't see from the postman. Do the client has to add the certificate in their system or do we need to place the certificate in on-prem server? Any thoughts or suggestion on how we can resolve this and what is causing this error?
Thanks in advance..