If any third party mail servers / REST endpoints/HTTPS endpoints that requires SSL is being used you probably do not need to care about the certificate, but in case the certificate is not trusted, the mail reader will not be able to establish a connection to the server. To mark a certificate as trusted you need to get hold of the actual certificate and import it to the keystore using the keytool command.

To trust a certificate you need to use the keytool command supplied with the JDK. You will need to locate the JDK used during runtime by your application server.
You can choose to create a new truststore or use the cacerts that comes with the java installation.
Example:
<java_home>/bin/keytool -import -alias <certificate-alias> -file <certificate.cer> -keystore <truststore> -storepass <thePassword>
 

Sources:
Configure the HTTP Transport Connector - Technical Documentation For IFS Cloud

Configure the REST Transport Connector - Technical Documentation For IFS Cloud

Configure the Mail Transport Connector - Technical Documentation For IFS Cloud

How could be this configuration done in Cloud? This documentation seem to be outdated.

If I know, there is no access to Docker container, where Server running. But maybe it is possible for OnPremise installation, but how it could be done on BuildPlace environments and Cloud hosted environments?

Thanks

BR