23.0.6 is up and running with even SAML 2.0 AD working solid running in a Docker Container.
Getting a Java Exception on email “Test Connection” button and have configured TLS 587 and valid email server. Testing email from the container to verify the environment, firewalls and misc using postfix/swaks and confirming email sent.
ERROR [org.keycloak.services] (executor-thread-16) KC-SERVICES0021: Failed to send email to confirm identity broker linking: org.keycloak.email.EmailException: java.lang.NullPointerException
keycloak.email.DefaultEmailSenderProvider] (executor-thread-16) Failed to get list of supported SSL protocols: java.security.NoSuchAlgorithmException: Error constructing implementation (algorithm: Default, provider: SunJSSE, class: sun.security.ssl.SSLContextImpl$DefaultSSLContext)
NoSuchAlgorithmException this means it’s an issue with the security provider configuration
It looks like your Keycloak container doesn’t supports the necessary SSL/TLS protocols. Try explicitly configuring the supported SSL/TLS protocols in your Keycloak configuration.
P.S. If your Java runtime is missing necessary security providers, you can install them. For example, for Debian-based systems, you can use: