FlowFromCode.java

public static void main(String... args) throws MuleException {
    Mule mule = Mule.newInstance(new AbstractModule() {
        @Override
        protected void configure() {
            flow("SendEmail")
                    .send("smtp://smtp.mycompany.com:25?address=#[header:address]");
        }
    });
    mule.start(); // start mule

    final Map<String, Object> properties = new HashMap<String, Object>(); //map that holds payload message properties

    properties.put("subject", "Look this cool feature!"); //email subject
    properties.put("address", "mule_users@mycompany.com"); //email address to send to
    final String mailContent = "Send emails direct from Mule DSL!"; //email content

    mule.flow("SendEmail").process(mailContent, properties); //executes flow passing as arguments the mailContent alongside message properties
}