@Service
    public class MailSenderService {
    
        private JavaMailSender javaMailSender;
    
        @Autowired
        public MailSenderService(JavaMailSender javaMailSender) {
            this.javaMailSender = javaMailSender;
        }
    
        @Value("${email.from.address}")
        private String fromAddress;
    
        public void sendMail(SendEmailRequest emailRequest) throws MessagingException {
            sendMailMultipart(emailRequest.getEmail(), emailRequest.getSubject(), emailRequest.getMessage(), null);
        }
    
        public void sendMail(SendEmailRequest emailRequest, File file) throws MessagingException {
            sendMailMultipart(emailRequest.getEmail(), emailRequest.getSubject(), emailRequest.getMessage(), file);
        }
    
        private void sendMailMultipart(String toEmail, String subject, String message, File file) throws MessagingException {
            MimeMessage mimeMessage = javaMailSender.createMimeMessage();
    
            MimeMessageHelper helper = new MimeMessageHelper(mimeMessage, true);
            helper.setFrom(fromAddress);
            helper.setTo(toEmail);
            helper.setSubject(subject);
            helper.setText(message);
    
            if (file != null) {
                helper.addAttachment(file.getName(), file);
            }
            javaMailSender.send(mimeMessage);
        }
    }