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Posted on Jul 19, 2022

Spring Boot – How to send email via SMTP

#spring #springboot

Project Directory

Maven

To send email, declares spring-boot-starter-mail, it will pull the JavaMail dependencies.

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.1</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>spring-boot-send-email</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>spring-boot-send-email</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-mail</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

Display the project dependencies.

mvn dependency:tree
[INFO] Scanning for projects...
[INFO] 
[INFO] -----------------< com.example:spring-boot-send-email >-----------------
[INFO] Building spring-boot-send-email 0.0.1-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] 
[INFO] --- maven-dependency-plugin:3.3.0:tree (default-cli) @ spring-boot-send-email ---
[INFO] com.example:spring-boot-send-email:jar:0.0.1-SNAPSHOT
[INFO] +- org.springframework.boot:spring-boot-starter-web:jar:2.7.1:compile
[INFO] |  +- org.springframework.boot:spring-boot-starter:jar:2.7.1:compile
[INFO] |  |  +- org.springframework.boot:spring-boot-starter-logging:jar:2.7.1:compile
[INFO] |  |  |  +- ch.qos.logback:logback-classic:jar:1.2.11:compile
[INFO] |  |  |  |  \- ch.qos.logback:logback-core:jar:1.2.11:compile
[INFO] |  |  |  +- org.apache.logging.log4j:log4j-to-slf4j:jar:2.17.2:compile
[INFO] |  |  |  |  \- org.apache.logging.log4j:log4j-api:jar:2.17.2:compile
[INFO] |  |  |  \- org.slf4j:jul-to-slf4j:jar:1.7.36:compile
[INFO] |  |  +- jakarta.annotation:jakarta.annotation-api:jar:1.3.5:compile
[INFO] |  |  \- org.yaml:snakeyaml:jar:1.30:compile
[INFO] |  +- org.springframework.boot:spring-boot-starter-json:jar:2.7.1:compile
[INFO] |  |  +- com.fasterxml.jackson.core:jackson-databind:jar:2.13.3:compile
[INFO] |  |  |  +- com.fasterxml.jackson.core:jackson-annotations:jar:2.13.3:compile
[INFO] |  |  |  \- com.fasterxml.jackson.core:jackson-core:jar:2.13.3:compile
[INFO] |  |  +- com.fasterxml.jackson.datatype:jackson-datatype-jdk8:jar:2.13.3:compile
[INFO] |  |  +- com.fasterxml.jackson.datatype:jackson-datatype-jsr310:jar:2.13.3:compile
[INFO] |  |  \- com.fasterxml.jackson.module:jackson-module-parameter-names:jar:2.13.3:compile
[INFO] |  +- org.springframework.boot:spring-boot-starter-tomcat:jar:2.7.1:compile
[INFO] |  |  +- org.apache.tomcat.embed:tomcat-embed-core:jar:9.0.64:compile
[INFO] |  |  +- org.apache.tomcat.embed:tomcat-embed-el:jar:9.0.64:compile
[INFO] |  |  \- org.apache.tomcat.embed:tomcat-embed-websocket:jar:9.0.64:compile
[INFO] |  +- org.springframework:spring-web:jar:5.3.21:compile
[INFO] |  |  \- org.springframework:spring-beans:jar:5.3.21:compile
[INFO] |  \- org.springframework:spring-webmvc:jar:5.3.21:compile
[INFO] |     +- org.springframework:spring-aop:jar:5.3.21:compile
[INFO] |     +- org.springframework:spring-context:jar:5.3.21:compile
[INFO] |     \- org.springframework:spring-expression:jar:5.3.21:compile
[INFO] +- org.springframework.boot:spring-boot-devtools:jar:2.7.1:runtime
[INFO] |  +- org.springframework.boot:spring-boot:jar:2.7.1:compile
[INFO] |  \- org.springframework.boot:spring-boot-autoconfigure:jar:2.7.1:compile
[INFO] +- org.springframework.boot:spring-boot-configuration-processor:jar:2.7.1:compile
[INFO] +- org.springframework.boot:spring-boot-starter-test:jar:2.7.1:test
[INFO] |  +- org.springframework.boot:spring-boot-test:jar:2.7.1:test
[INFO] |  +- org.springframework.boot:spring-boot-test-autoconfigure:jar:2.7.1:test
[INFO] |  +- com.jayway.jsonpath:json-path:jar:2.7.0:test
[INFO] |  |  +- net.minidev:json-smart:jar:2.4.8:test
[INFO] |  |  |  \- net.minidev:accessors-smart:jar:2.4.8:test
[INFO] |  |  |     \- org.ow2.asm:asm:jar:9.1:test
[INFO] |  |  \- org.slf4j:slf4j-api:jar:1.7.36:compile
[INFO] |  +- jakarta.xml.bind:jakarta.xml.bind-api:jar:2.3.3:test
[INFO] |  |  \- jakarta.activation:jakarta.activation-api:jar:1.2.2:test
[INFO] |  +- org.assertj:assertj-core:jar:3.22.0:test
[INFO] |  +- org.hamcrest:hamcrest:jar:2.2:test
[INFO] |  +- org.junit.jupiter:junit-jupiter:jar:5.8.2:test
[INFO] |  |  +- org.junit.jupiter:junit-jupiter-api:jar:5.8.2:test
[INFO] |  |  |  +- org.opentest4j:opentest4j:jar:1.2.0:test
[INFO] |  |  |  +- org.junit.platform:junit-platform-commons:jar:1.8.2:test
[INFO] |  |  |  \- org.apiguardian:apiguardian-api:jar:1.1.2:test
[INFO] |  |  +- org.junit.jupiter:junit-jupiter-params:jar:5.8.2:test
[INFO] |  |  \- org.junit.jupiter:junit-jupiter-engine:jar:5.8.2:test
[INFO] |  |     \- org.junit.platform:junit-platform-engine:jar:1.8.2:test
[INFO] |  +- org.mockito:mockito-core:jar:4.5.1:test
[INFO] |  |  +- net.bytebuddy:byte-buddy:jar:1.12.11:test
[INFO] |  |  +- net.bytebuddy:byte-buddy-agent:jar:1.12.11:test
[INFO] |  |  \- org.objenesis:objenesis:jar:3.2:test
[INFO] |  +- org.mockito:mockito-junit-jupiter:jar:4.5.1:test
[INFO] |  +- org.skyscreamer:jsonassert:jar:1.5.0:test
[INFO] |  |  \- com.vaadin.external.google:android-json:jar:0.0.20131108.vaadin1:test
[INFO] |  +- org.springframework:spring-core:jar:5.3.21:compile
[INFO] |  |  \- org.springframework:spring-jcl:jar:5.3.21:compile
[INFO] |  +- org.springframework:spring-test:jar:5.3.21:test
[INFO] |  \- org.xmlunit:xmlunit-core:jar:2.9.0:test
[INFO] \- org.springframework.boot:spring-boot-starter-mail:jar:2.7.1:compile
[INFO]    +- org.springframework:spring-context-support:jar:5.3.21:compile
[INFO]    \- com.sun.mail:jakarta.mail:jar:1.6.7:compile
[INFO]       \- com.sun.activation:jakarta.activation:jar:1.2.2:compile
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  2.153 s
[INFO] Finished at: 2022-07-18T14:40:39+07:00
[INFO] ------------------------------------------------------------------------

Gmail SMTP

This example is using Gmail SMTP server, tested with TLS (port 587) and SSL (port 465). Read this Gmail SMTP

application.properties

Note

For Gmail SMTP, if your account is enabled the 2-Step verification, please create an App Password

Access link: https://support.google.com/accounts/answer/185833?p=InvalidSecondFactor
URL : https://myaccount.google.com/security Puts the newly generated app password into spring.mail.password.

Sending Email

Spring provides an JavaMailSender interface on top of JavaMail APIs.

Send a normal text email
Send an HTML email and a file attachment.

Demo

Start Spring Boot, and it will send out an email.

package com.example.sendemail;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.core.io.ClassPathResource;
import org.springframework.mail.SimpleMailMessage;
import org.springframework.mail.javamail.JavaMailSender;
import org.springframework.mail.javamail.MimeMessageHelper;

import javax.mail.MessagingException;
import javax.mail.internet.MimeMessage;
import java.io.IOException;

@SpringBootApplication
public class SpringBootSendEmailApplication implements CommandLineRunner {
    @Autowired
    private JavaMailSender javaMailSender;
    public static void main(String[] args) {
        SpringApplication.run(SpringBootSendEmailApplication.class, args);
    }

    @Override
    public void run(String... args) throws Exception {
        System.out.println("Sending Email...");
        sendEmail();
        System.out.println("Done");
    }

    void sendEmailWithAttachment() throws MessagingException, IOException {
        MimeMessage msg = javaMailSender.createMimeMessage();
        MimeMessageHelper helper = new MimeMessageHelper(msg, true);
        helper.setTo("hauntps@gmail.com");
        helper.setSubject("Testing from Spring Boot");
        helper.setText("<h1>Check attachment for image!</h1>", true);
        helper.addAttachment("my_photo.png", new ClassPathResource("android.png"));
        javaMailSender.send(msg);

    }
    void sendEmail() {
        SimpleMailMessage msg = new SimpleMailMessage();
        msg.setTo("hauntps@gmail.com", "ngocnt@gmail.com");
        msg.setSubject("Testing from Spring Boot");
        msg.setText("Hello World \n Spring Boot Email");
        javaMailSender.send(msg);
    }

}

Source code

https://github.com/java-cake/spring-boot/tree/main/spring-boot-send-email

DEV Community

Spring Boot – How to send email via SMTP

Project Directory

Maven

Gmail SMTP

Note

Sending Email

Demo

Source code

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