code: public SendEmailResponse sendEmail(String from, String displayName, String[] toAddr, String subject, String body,
              File...attachmentFiles) {
          SendEmailRequest request =
                  buildSendEmailRequest(from, from, from, toAddr, new String[] { "" }, new String[] { "" }, subject,
                          body, 1, 1);
          request = fillDisplayName(request, displayName);
          request = fillAttachment(request, attachmentFiles);
  
          return sendEmail(request);
      }
docs: Send email.
  <p>
  Simple to send email, all optional parameters use system default value.
  
  @param from The sender, which is required
  @param displayName The display name of sender, which can be custom by the users themselves
  @param toAddr The receive, which is required
  @param subject The title of the email, which is required
  @param body The content of the email, which is required
  @param attachmentFiles The array of attachment file. If you need send attachment then set it, it's optional
  parameters
  
  @see com.baidubce.services.ses.SesClient#sendEmail(com.baidubce.services.ses.model.SendEmailRequest request)