sendgrid-java

package com.aironman;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;

public class SendEmail {

	public static void main(String[] args) throws IOException {

		if (args.length != 3) {
			System.out.println("USAGE: java -cp target/MyStreamjava8-1.0.1-RELEASE.jar com.aironman.SendEmail PATH_TO_final_output_winners.txt PATH_TO_final_output_star.txt correo_destino");
			System.exit(-1);
		}
		String path_to_winners = args[0];
		String path_to_stars = args[1];
		String email = args[2];

		String content_path_to_winners = new String(Files.readAllBytes(Paths.get(path_to_winners)));
		String content_path_to_stars = new String(Files.readAllBytes(Paths.get(path_to_stars)));
		StringBuffer sb = new StringBuffer();
		sb.append(content_path_to_winners);
		sb.append(content_path_to_stars);
		String subject = "Resultados_" + new java.util.Date();
		boolean ret = EmailSenderService.sendEmail(sb.toString(),subject ,email);
		System.out.println("Done! " + ret );
		System.exit(0);
	}
}

package com.aironman;

import java.io.IOException;

import com.sendgrid.Content;
import com.sendgrid.Email;
import com.sendgrid.Mail;
import com.sendgrid.Method;
import com.sendgrid.Request;
import com.sendgrid.Response;
import com.sendgrid.SendGrid;

public class EmailSenderService {

	public final static boolean sendEmail(String body, String _subject, String _to) {

		boolean ret = true;
		Email from = new Email("alonsoir@gmail.com");
		String subject = _subject;
		Email to = new Email(_to);
		Content content = new Content("text/plain", body);
		Mail mail = new Mail(from, subject, to, content);

		SendGrid sg = new SendGrid("MY-API-KEY");
		Request request = new Request();
		try {
			request.setMethod(Method.POST);
			request.setEndpoint("mail/send");
			request.setBody(mail.build());
			Response response = sg.api(request);
			System.out.println("StatusCode: " + response.getStatusCode());
			System.out.println("response.getBody: " + response.getBody());
			System.out.println("response.getHeaders: " + response.getHeaders());
		} catch (IOException ex) {
			System.out.println(ex.getLocalizedMessage());
			ret = false;
		}
		return ret;
	}
}

I am using this dependency in the pom.xml file

<!-- https://mvnrepository.com/artifact/com.sendgrid/sendgrid-java -->
		<dependency>
			<groupId>com.sendgrid</groupId>
			<artifactId>sendgrid-java</artifactId>
			<version>4.3.0</version>
		</dependency>