Could not sent mail from gmail in java

A common issue!

There are several reasons why you might not be able to send an email from Gmail using Java. Here are some common issues and solutions:

SMTP Authentication: Gmail requires SMTP authentication to send emails. Make sure you're using the correct username and password.
SMTP Port: Gmail uses port 587 for SMTP authentication. Check your Java code to ensure you're using the correct port.
SSL/TLS: Gmail requires SSL/TLS encryption for secure connections. Ensure your Java code is using SSL/TLS.
Firewall or Proxy Issues: If you're behind a firewall or proxy, it might be blocking the connection. Check your network settings and firewall rules.
Gmail's SMTP Server: Gmail's SMTP server is smtp.gmail.com. Make sure you're using the correct server address.

Here's an example of a simple Java code snippet that sends an email using Gmail:

import javax.mail.*;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;

public class SendEmail {
    public static void main(String[] args) {
        Properties props = new Properties();
        props.put("mail.smtp.host", "smtp.gmail.com");
        props.put("mail.smtp.port", 587);
        props.put("mail.smtp.auth", "true");
        props.put("mail.smtp.starttls.enable", "true");

        Session session = Session.getInstance(props, new Authenticator() {
            @Override
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication("your-gmail-username", "your-gmail-password");
            }
        });

        try {
            Message message = new MimeMessage(session);
            message.setFrom(new InternetAddress("[email protected]"));
            message.setRecipients(Message.RecipientType.TO, InternetAddress.parse("[email protected]"));
            message.setSubject("Test Email");
            message.setText("Hello, this is a test email from Java!");

            Transport.send(message);

            System.out.println("Email sent successfully!");
        } catch (MessagingException e) {
            System.out.println("Error sending email: " + e.getMessage());
        }
    }
}

Make sure to replace your-gmail-username and your-gmail-password with your actual Gmail credentials.

If you're still having issues, try the following:

Enable "Less secure app access" in your Google Account settings. This allows less secure apps to access your account.
Check your Java code for any syntax errors or typos.
Verify that your Gmail account is not blocked or suspended.
Try using a different email client or library to send the email.

If none of these solutions work, please provide more details about your Java code and the error message you're receiving, and I'll be happy to help you troubleshoot the issue!

Mail Knowledge

Could not sent mail from gmail in java