Guide to sending email with JavaMailer using SpringBoot with your GMAIL

Getting Started

1. Add the Java mail dependency in your pom.xml

     <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-mail</artifactId>
     </dependency>
   

2. Optional but important add the dotenv dependency in your pom.xml

     <dependency>
        <groupId>io.github.cdimascio</groupId>
        <artifactId>dotenv-java</artifactId>
        <version>2.3.1</version>
     </dependency>
   

3. Optional but important create a .env file in the project root folder and add the details below in it. Once done, open .gitignore file and add .env (i.e. write .env)

     EMAIL_ADDRESS=yourgmail@gmail.com
     PASSWORD=your-password
   

4. Create a Bean of JavaMailSender (if you choose this option skip no. 5. This is the option i will use) or do add it in your application.properties file (5)

     @Bean
     public JavaMailSender getJavaMailSender() {
        Dotenv dotenv = Dotenv.load(); 
        String email = dotenv.get("EMAIL_ADDRESS"); //you can add your email here if you did not set up .env file
        String password = dotenv.get("PASSWORD");   //you can add your password here if you did not set up .env file
   
        JavaMailSenderImpl mailSender = new JavaMailSenderImpl();
        mailSender.setHost("smtp.gmail.com");
        mailSender.setPort(587);
        mailSender.setUsername(email);
        mailSender.setPassword(password);
   
        Properties props = mailSender.getJavaMailProperties();
        props.put("mail.transport.protocol", "smtp");
        props.put("mail.smtp.auth", "true");
        props.put("mail.smtp.starttls.enable", "true");
        props.put("mail.debug", "true");
   
        return mailSender;
     }
   

5. Application.properties file if you do not want to create a Bean of JavaMailerSender

     spring.mail.host=smtp.gmail.com
     spring.mail.port=587
     spring.mail.username=yourgmail@gmail.com
     spring.mail.password=yourpassword@gmail.com
     spring.mail.properties.mail.smtp.auth=true
     spring.mail.properties.mail.smtp.starttls.enable=true
   

6. The last step is to send email:

    SimpleMailMessage message = new SimpleMailMessage();
    message.setTo("toemail@email.com");
    message.setSentDate(new Date());
    message.setSubject("Your subject");
    message.setText("Your message body");
   
    try {
        javaMailSender.send(message);
    } catch (Exception e) {
        System.out.println("ERROR: " + e.getMessage());
    }
   

7. If you experience this error:

     https://support.google.com/mail/?p=BadCredentials
   

8. This is because Google allows you to generate specific credentials for apps. This is superior to using 'your own' account credentials. This means you will need to enable a two factor verification and create app specific password.

9. Follow this guide How to Create App-Specific Passwords in Gmail

Reference Documentation

1. Guide to Spring Email
2. How to Create App-Specific Passwords in Gmail