public String makeVerificationCode() { //인증 코드 생성
        Random random = new Random();
        return String.format("%06d", random.nextInt(999999));
    }

    public MailSend sendVerificationEmail(String email, String code) {
        try {
            EmailVerification verification = new EmailVerification(email, code);

            MimeMessage message = mailSender.createMimeMessage();
            MimeMessageHelper messageHelper = new MimeMessageHelper(message, true);

            messageHelper.setTo(email);
            messageHelper.setSubject(SUBJECT);
            String htmlContent = getVerificationMessage(code);
            messageHelper.setText(htmlContent, true);

            if (emailVerificationRepository.existsById(getRedisKey(email))) { //redis에 email이 있으면 삭제
                emailVerificationRepository.deleteById(getRedisKey(email));
            }
            emailVerificationRepository.save(verification); //Redis에 인증 코드 저장
            mailSender.send(message);

        } catch (MessagingException e) {
            e.printStackTrace();
            return emailConverter.toMailSendResponse("메일 전송에 실패했습니다.", false);
        }
        return emailConverter.toMailSendResponse("메일 전송에 성공했습니다.", true);
    }

public MailVerify verifyCode(String email, String code) { //메일 검증
        Optional<EmailVerification> verificationObject = emailVerificationRepository.findById(email); // redis에서 객체 가져오기
        boolean check = false;
        if (verificationObject.isPresent()) { //객체 존재하는지
            EmailVerification verification = verificationObject.get();
            if (verification.getVerificationCode().equals(code)) { // value를 확인해 입력 인증번호가 같은지 확인
                emailVerificationRepository.deleteById(email);
                check = true;
            }
        }
        return emailConverter.toMailVerifyResponse(check, email);
    }