Email Dependencies

Introduction

Almost every real application needs to send email at some point — a welcome email after signup, a password reset link, an order confirmation, or an alert when something goes wrong. Spring Boot ships a dedicated starter for exactly this: spring-boot-starter-mail.

It wraps the JavaMail API in a much friendlier Spring abstraction called JavaMailSender, and it auto-configures itself from a handful of properties, so you can go from "no email support" to "sending emails" in a few minutes.

Why You Need This Dependency

Use case: any feature that needs to notify a user outside the application itself — account verification, password resets, invoices, marketing digests, or system alerts to an operations team. Without this starter, you would have to manually configure the raw JavaMail API, which is verbose and easy to get wrong (session properties, transport protocols, authenticators).

Adding the Dependency

Add spring-boot-starter-mail to your pom.xml. It pulls in the Jakarta Mail API and Spring's mail abstraction, and Spring Boot auto-configures a JavaMailSender bean as soon as mail properties are present.

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

Configuring Mail Properties

Configure your SMTP server in application.properties. Here is a typical Gmail SMTP setup (for production, use a transactional email provider such as SendGrid, Amazon SES, or Mailgun instead of a personal Gmail account).

spring.mail.host=smtp.gmail.com
spring.mail.port=587
spring.mail.username=your-email@gmail.com
spring.mail.password=your-app-password
spring.mail.properties.mail.smtp.auth=true
spring.mail.properties.mail.smtp.starttls.enable=true

Sending a Simple Email

Once the properties above are present, Spring Boot auto-configures a JavaMailSender bean you can inject anywhere. SimpleMailMessage is the easiest way to send a plain text email.

@Service
public class EmailService {

    private final JavaMailSender mailSender;

    public EmailService(JavaMailSender mailSender) {
        this.mailSender = mailSender;
    }

    public void sendWelcomeEmail(String to, String username) {
        SimpleMailMessage message = new SimpleMailMessage();
        message.setTo(to);
        message.setSubject("Welcome to PrograMinds!");
        message.setText("Hi " + username + ",\n\nThanks for signing up. Happy learning!");
        mailSender.send(message);
    }
}

Sending an HTML Email

Most real-world emails need formatting, links, and images, which SimpleMailMessage cannot do. For that, build a MimeMessage and use MimeMessageHelper to set HTML content.

public void sendOrderConfirmation(String to, String orderId) throws MessagingException {
    MimeMessage message = mailSender.createMimeMessage();
    MimeMessageHelper helper = new MimeMessageHelper(message, true, "UTF-8");

    String html = """
            <h2>Order Confirmed</h2>
            <p>Your order <strong>%s</strong> has been placed successfully.</p>
            <p><a href=\"https://example.com/orders/%s\">Track your order</a></p>
            """.formatted(orderId, orderId);

    helper.setTo(to);
    helper.setSubject("Order Confirmation - " + orderId);
    helper.setText(html, true);

    mailSender.send(message);
}

Common Mistakes

Best Practices

Frequently Asked Questions

Summary

spring-boot-starter-mail gives you a JavaMailSender bean auto-configured from simple properties, letting you send both plain text and rich HTML emails with just a few lines of code.