Enable email client for Activiti / Flowable. They provide a means to configure it using their SDK.
May add configuration or perhaps we can borrow config from our IDM email client.
OPENIDM-11370 for details.
See org.forgerock.openidm.workflow.activiti.impl.WorkflowConfig for existing email config fields.
We should try to support same general mail server config options that we do in org.forgerock.openidm.external.email.impl.EmailClient