spring-mail

Spring Mail

Quick Start

# application.yml
spring:
  mail:
    host: smtp.gmail.com
    port: 587
    username: ${MAIL_USERNAME}
    password: ${MAIL_PASSWORD}
    properties:
      mail:
        smtp:
          auth: true
          starttls:
            enable: true

@Service
@RequiredArgsConstructor
public class EmailService {

    private final JavaMailSender mailSender;

    public void sendSimpleEmail(String to, String subject, String text) {
        SimpleMailMessage message = new SimpleMailMessage();
        message.setTo(to);
        message.setSubject(subject);
        message.setText(text);
        message.setFrom("[email protected]");

        mailSender.send(message);
    }
}

Configuration

@Configuration
public class MailConfig {

    @Bean
    public JavaMailSender javaMailSender(MailProperties props) {
        JavaMailSenderImpl mailSender = new JavaMailSenderImpl();
        mailSender.setHost(props.getHost());
        mailSender.setPort(props.getPort());
        mailSender.setUsername(props.getUsername());
        mailSender.setPassword(props.getPassword());

        Properties javaMailProperties = new Properties();
        javaMailProperties.put("mail.smtp.auth", true);
        javaMailProperties.put("mail.smtp.starttls.enable", true);
        javaMailProperties.put("mail.smtp.connectiontimeout", 5000);
        javaMailProperties.put("mail.smtp.timeout", 5000);
        javaMailProperties.put("mail.smtp.writetimeout", 5000);

        mailSender.setJavaMailProperties(javaMailProperties);
        return mailSender;
    }
}

MimeMessage (HTML & Attachments)

@Service
@RequiredArgsConstructor
@Slf4j
public class EmailService {

    private final JavaMailSender mailSender;

    // HTML Email
    public void sendHtmlEmail(String to, String subject, String htmlContent)
            throws MessagingException {
        MimeMessage message = mailSender.createMimeMessage();
        MimeMessageHelper helper = new MimeMessageHelper(message, true, "UTF-8");

        helper.setTo(to);
        helper.setSubject(subject);
        helper.setText(htmlContent, true);  // true = HTML
        helper.setFrom("[email protected]");

        mailSender.send(message);
    }

    // Email con attachment
    public void sendEmailWithAttachment(String to, String subject, String text,
                                        String attachmentPath) throws MessagingException {
        MimeMessage message = mailSender.createMimeMessage();
        MimeMessageHelper helper = new MimeMessageHelper(message, true);

        helper.setTo(to);
        helper.setSubject(subject);
        helper.setText(text);
        helper.setFrom("[email protected]");

        FileSystemResource file = new FileSystemResource(new File(attachmentPath));
        helper.addAttachment(file.getFilename(), file);

        mailSender.send(message);
    }

    // Email con inline image
    public void sendEmailWithInlineImage(String to, String subject,
                                         String htmlContent, String imagePath)
            throws MessagingException {
        MimeMessage message = mailSender.createMimeMessage();
        MimeMessageHelper helper = new MimeMessageHelper(message, true);

        helper.setTo(to);
        helper.setSubject(subject);
        // Reference: <img src="cid:logo">
        helper.setText(htmlContent, true);
        helper.setFrom("[email protected]");

        FileSystemResource image = new FileSystemResource(new File(imagePath));
        helper.addInline("logo", image);

        mailSender.send(message);
    }

    // Multiple recipients
    public void sendToMultiple(String[] to, String[] cc, String[] bcc,
                               String subject, String text) throws MessagingException {
        MimeMessage message = mailSender.createMimeMessage();
        MimeMessageHelper helper = new MimeMessageHelper(message);

        helper.setTo(to);
        if (cc != null) helper.setCc(cc);
        if (bcc != null) helper.setBcc(bcc);
        helper.setSubject(subject);
        helper.setText(text);
        helper.setFrom("[email protected]");

        mailSender.send(message);
    }
}