Sending email using Java and Spring Boot - spring-boot

Question

I am new to sending email using java. I have a Spring Boot project from where I want to send email. I have tried several examples available on internet. Giving the URL of two examples which I tried:
https://www.mkyong.com/spring-boot/spring-boot-how-to-send-email-via-smtp/
https://www.mkyong.com/java/javamail-api-sending-email-via-gmail-smtp-example/
But none is working. Can anyone say me what customizations I will have to do in these examples and which values I will have to change to make them working? Like I will change the to Address to the adress where I will have to send email, what is the username and password? Whose username, password are they?

Answer 1

You can use Sendgrid API. You can send 100 email per day without paying it's absolutely free. Need to create Sendgrid account and generate an API key to send emails.
Reference:
https://sendgrid.com/docs/for-developers/sending-email/v3-java-code-example/

Answer 2

There is Ogham library. The code to send email is easy to write and you can even use a template to write the content of your email. It is easier to use than other libraries because you don't need to handle technical concerns (like inlining images and styles in the HTML, it is done automatically).
You can even test your code locally with a SMTP server to check the result of your email before sending it through a SMTP provider.
The email can be sent either using SMTP protocol or through providers API (like SendGrid).
It is compatible with Spring Boot and even easier to use because you don't need to instantiate the service.
package fr.sii.ogham.sample.springboot.email;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.PropertySource;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.bind.annotation.RestController;
import fr.sii.ogham.core.exception.MessagingException;
import fr.sii.ogham.core.service.MessagingService;
import fr.sii.ogham.email.message.Email;
#SpringBootApplication
#PropertySource("application-email-basic.properties") // just needed to be able to run the sample
public class BasicSample {
public static void main(String[] args) throws MessagingException {
SpringApplication.run(BasicSample.class, args);
}
#RestController
public static class EmailController {
// Messaging service is automatically created using Spring Boot features
// The configuration can be set into application-email-basic.properties
// The configuration files are stored into src/main/resources
#Autowired
MessagingService messagingService;
#PostMapping(value="api/email/basic")
#ResponseStatus(HttpStatus.CREATED)
public void sendMail(#RequestParam("subject") String subject, #RequestParam("content") String content, #RequestParam("to") String to) throws MessagingException {
// send the email using fluent API
messagingService.send(new Email()
.subject(subject)
.body().string(content)
.to(to));
}
}
}
There are many other features and samples / spring samples.