@Test
    void verifyOperation() throws Exception {
        assertNotNull(emailSender);
        val principal = RegisteredServiceTestUtils.getPrincipal("casuser",
            Map.of("email", List.of("example@gmail.com")));
        val emailRequest = EmailMessageRequest.builder()
            .locale(Locale.GERMANY)
            .body("This is the email body")
            .emailProperties(new EmailProperties()
                .setSubject("This is the subject")
                .setFrom("person@gmail.com"))
            .attribute("email")
            .principal(principal)
            .build();
        assertFalse(emailSender.send(emailRequest).isSuccess());
    }
This is {@link MailjetEmailSenderTests}.

@author Misagh Moayyed
@since 7.1.0
support/cas-server-support-mailjet/src/test/java/org/apereo/cas/mail/MailjetEmailSenderTests.java