1 EmailUpdated.java

@Value
public class EmailUpdated implements Event {

    public static final String EXCHANGE_NAME = "email.updated.exchange";

    String accountId;
    String oldEmail;
    String newEmail;
}

2 AccountSettingsController.java

eventsService.fire(new EmailUpdated(accountId, oldEmail, newEmail));

3 MailChimpSynchronization.java

@RabbitEventListener(queue = "some.queue")
public void emailUpdated(EmailUpdated event) {
    doSomethingWith(event.getOldEmail(), event.getNewEmail());
}