protected boolean isNotificationSent(final Principal principal, final Ticket token) {
        return communicationsManager.isNotificationSenderDefined()
            && communicationsManager.notify(principal, "Apereo CAS Token", String.format("Token: %s", token.getId()));
    }
Event attribute to allow registration of email.
support/cas-server-support-simple-mfa-core/src/main/java/org/apereo/cas/mfa/simple/web/flow/CasSimpleMultifactorSendTokenAction.java