API JavaMail для JavaMail – Отправка электронной почты через пример SMTP Gmail

	
		com.sun.mail
		javax.mail
		1.6.2
	

SMTP = smtp.gmail.com 
Port = 587

package com.mkyong;

import javax.mail.*;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import java.util.Properties;

public class SendEmailTLS {

    public static void main(String[] args) {

        final String username = "username@gmail.com";
        final String password = "password";

        Properties prop = new Properties();
		prop.put("mail.smtp.host", "smtp.gmail.com");
        prop.put("mail.smtp.port", "587");
        prop.put("mail.smtp.auth", "true");
        prop.put("mail.smtp.starttls.enable", "true"); //TLS
        
        Session session = Session.getInstance(prop,
                new javax.mail.Authenticator() {
                    protected PasswordAuthentication getPasswordAuthentication() {
                        return new PasswordAuthentication(username, password);
                    }
                });

        try {

            Message message = new MimeMessage(session);
            message.setFrom(new InternetAddress("from@gmail.com"));
            message.setRecipients(
                    Message.RecipientType.TO,
                    InternetAddress.parse("to_username_a@gmail.com, to_username_b@yahoo.com")
            );
            message.setSubject("Testing Gmail TLS");
            message.setText("Dear Mail Crawler,"
                    + "\n\n Please do not spam my email!");

            Transport.send(message);

            System.out.println("Done");

        } catch (MessagingException e) {
            e.printStackTrace();
        }
    }

}

SMTP = smtp.gmail.com 
Port = 465

package com.mkyong;

import javax.mail.*;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import java.util.Properties;

public class SendEmailSSL {

    public static void main(String[] args) {

        final String username = "username@gmail.com";
        final String password = "password";

        Properties prop = new Properties();
		prop.put("mail.smtp.host", "smtp.gmail.com");
        prop.put("mail.smtp.port", "465");
        prop.put("mail.smtp.auth", "true");
        prop.put("mail.smtp.socketFactory.port", "465");
        prop.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
        
        Session session = Session.getInstance(prop,
                new javax.mail.Authenticator() {
                    protected PasswordAuthentication getPasswordAuthentication() {
                        return new PasswordAuthentication(username, password);
                    }
                });

        try {

            Message message = new MimeMessage(session);
            message.setFrom(new InternetAddress("from@gmail.com"));
            message.setRecipients(
                    Message.RecipientType.TO,
                    InternetAddress.parse("to_username_a@gmail.com, to_username_b@yahoo.com")
            );
            message.setSubject("Testing Gmail SSL");
            message.setText("Dear Mail Crawler,"
                    + "\n\n Please do not spam my email!");

            Transport.send(message);

            System.out.println("Done");

        } catch (MessagingException e) {
            e.printStackTrace();
        }
    }

}

Caused by: javax.mail.AuthenticationFailedException: 534-5.7.9 Application-specific password required. Learn more at
534 5.7.9  https://support.google.com/mail/?p=InvalidSecondFactor - gsmtp

	at com.sun.mail.smtp.SMTPTransport$Authenticator.authenticate(SMTPTransport.java:965)
	at com.sun.mail.smtp.SMTPTransport.authenticate(SMTPTransport.java:876)
	at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:780)
	at javax.mail.Service.connect(Service.java:388)
	at javax.mail.Service.connect(Service.java:246)
	at javax.mail.Service.connect(Service.java:195)
	at javax.mail.Transport.send0(Transport.java:254)
	at javax.mail.Transport.send(Transport.java:124)
	at com.mkyong.calculator.SendEmail.main(SendEmail.java:41)

package com.mkyong;

import javax.mail.*;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import java.util.Properties;

public class SendEmail {

    public static void main(String[] args) {

        final String username = "username@gmail.com";
        final String password = "puts your app password here"; // update here

		// same code...
    }

}