I have a project with Java 17 and Spring 3. In my pom.xml the Test extensions are the following:

• junit-jupiter: version 5.10.1.
• mockito-core: version 5.8.0.
• mockito-junit-jupiter: version 5.8.0

I have the following class:

@Service
public class MailServiceImpl implements MailService {

    @Autowired
    private JavaMailSender mailSender;

    @Value("${mail.senderUsername}")
    private String mailSenderUsername;

    @Override
    public void sendMailConfirmationToken(MailSimpleRequest mailRequest) throws MessagingException {
        MimeMessage mimeMessage = mailSender.createMimeMessage();
        MimeMessageHelper message = new MimeMessageHelper(mimeMessage, true, "UTF-8");

        message.setFrom(mailSenderUsername);
        message.setTo(mailRequest.toUsers());
        message.setSubject(mailRequest.subject());
        message.setText("<div><p>Message</p></div>", true);

        this.mailSender.send(mimeMessage);
    }

}

I am doing the following test:

@ExtendWith(MockitoExtension.class)
class MailServiceImplTest {

    @Mock
    private JavaMailSender mailSender;

    @Mock
    private MimeMessage mimeMessage;

    @Mock
    private MimeMessageHelper mimeMessageHelper;

    private final MailSimpleRequest mailRequest = Data.givenMailRequest();

    @InjectMocks
    private MailServiceImpl mailService;

    @Test
    void sendMailConfirmationToken() throws MessagingException {
        when(mailSender.createMimeMessage()).thenReturn(mimeMessage);

        mailService.sendMailConfirmationToken(mailRequest);

        verify(mailSender).send(any(MimeMessage.class));
    }
}

When I verify the test, it gives me the following error:

OpenJDK 64-Bit Server VM warning: Sharing is only supported for boot loader classes because bootstrap classpath has been appended

java.lang.IllegalArgumentException: From address must not be null

    at org.springframework.util.Assert.notNull(Assert.java:172)
    at org.springframework.mail.javamail.MimeMessageHelper.setFrom(MimeMessageHelper.java:571)
    at ms.mailsender.service.impl.MailServiceImpl.sendMailConfirmationToken(MailServiceImpl.java:40)
    at ms.mailsender.service.impl.MailServiceImplTest.sendMailConfirmationToken(MailServiceImplTest.java:52)
    at java.base/java.lang.reflect.Method.invoke(Method.java:568)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)

¿Does anyone know how it can be solved??