GmailSMTPTest.java

import java.util.*;            
import javax.mail.*;          
import javax.mail.internet.*; 

public class GmailSMTPTest {
    public static void main(String[] args) {
        String from = "your.email@gmail.com";
        String password = "your-app-password";
        String to = "receiver@example.com";

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

        try {
            Message msg = new MimeMessage(session);
            msg.setFrom(new InternetAddress(from));
            msg.setRecipients(Message.RecipientType.TO, InternetAddress.parse(to));
            msg.setSubject("Test Email");
            msg.setText("Hello from Java!");

            Transport.send(msg);
            System.out.println("✅ Email sent!");

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