451 5.7.3 starttls is required to send mail java

A Java-related question!

The error message "451 5.7.3 StartTLS is required to send mail" indicates that the mail server you're trying to connect to requires the use of StartTLS (Transport Layer Security) encryption to send mail.

Here's a breakdown of the error message:

"451" is a SMTP response code indicating a temporary failure.
"5.7.3" is a specific error code indicating that the mail server requires StartTLS encryption.
"StartTLS is required to send mail" is a human-readable message explaining the reason for the error.

To resolve this issue in your Java application, you'll need to enable StartTLS encryption when connecting to the mail server. Here are some steps to help you achieve this:

Use a Java Mail API library: You'll need a Java library that provides a simple way to send emails. Some popular options include JavaMail, Apache Commons Email, and Spring Mail.
Configure the mail server settings: Set the mail server's host, port, username, and password in your Java code. You may also need to specify the encryption protocol (e.g., TLS or SSL).
Enable StartTLS encryption: Use the Java Mail API library to enable StartTLS encryption when connecting to the mail server. This typically involves setting a property or parameter on the Session or Transport object.

Here's some sample Java code using JavaMail to illustrate the process:

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

// Create a Properties object
Properties props = new Properties();
props.put("mail.smtp.host", "your.mail.server.host");
props.put("mail.smtp.port", "587"); // or 25, depending on your mail server
props.put("mail.smtp.starttls.enable", "true"); // Enable StartTLS encryption
props.put("mail.smtp.auth", "true"); // Enable authentication

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

// Create a MimeMessage object
MimeMessage message = new MimeMessage(session);

// Set the message's sender and recipient
message.setFrom(new InternetAddress("[email protected]"));
message.addRecipient(Message.RecipientType.TO, new InternetAddress("[email protected]"));

// Set the message's subject and body
message.setSubject("Test email");
message.setText("This is a test email.");

// Send the message
Transport.send(message);

In this example, we set the mail.smtp.starttls.enable property to true to enable StartTLS encryption. We also set the mail.smtp.auth property to true to enable authentication.

By following these steps and configuring your Java code to use StartTLS encryption, you should be able to resolve the "451 5.7.3 StartTLS is required to send mail" error and successfully send emails using your Java application.

Mail Knowledge

451 5.7.3 starttls is required to send mail java