我正在使用 JavaMailSender 类通过smtp协议向microsoft团队频道添加新邮件。它工作正常，但我需要创建公告，而不是默认的对话消息。有什么办法可以实现吗？
我正在使用spring框架和javamailsenderimpl类向团队发送消息。也许我应该添加一些标题或类似的smth来发送公告，而不是会话消息？

@RequiredArgsConstructor
@Slf4j
public class DefaultTeamsService implements TeamsService{
    private final JavaMailSender mailSender;
    @Value("${app.mail.from}")
    private String from;

    @Override
    public void sendMessage(String to, String subject, String html) {
        try {
            MimeMessage message = formMessage(from, to, subject, html);
            mailSender.send(message);
        } catch (MessagingException e) {
            log.error("Failed to form message", e);
        }
    }

    private MimeMessage formMessage(String from, String to, String subject, String html) throws MessagingException {
        MimeMessage message = mailSender.createMimeMessage();
        message.setSubject("", "utf-8");

        MimeMessageHelper helper = new MimeMessageHelper(message, true, "UTF-8");

        helper.setFrom(from);
        helper.setTo(to);
        helper.setSubject(subject);
        helper.setText(html, true);

        return message;
    }

现在就是这样
应该是这样的