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javax.mail.MessagingException: Could not connect to SMTP host: localhost, port: 25

由 生来就可爱ヽ(ⅴ＜●) 提交于 2019-12-05 01:31:32 
package sn;
import java.util.Date;
import java.util.Properties;
import javax.mail.Authenticator;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.AddressException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
public class SendEmail {
  public static void main(String[] args) {
  final String SSL_FACTORY = "javax.net.ssl.SSLSocketFactory";
  // Get a Properties object
     Properties props = System.getProperties();
     props.setProperty("mail.smtp.host", "smtp.gmail.com");
     props.setProperty("mail.smtp.socketFactory.class", SSL_FACTORY);
     props.setProperty("mail.smtp.socketFactory.fallback", "false");
     props.setProperty("mail.smtp.port", "465");
     props.setProperty("mail.smtp.socketFactory.port", "465");
     props.put("mail.smtp.auth", "true");
     props.put("mail.debug", "true");
     props.put("mail.store.protocol", "pop3");
     props.put("mail.transport.protocol", "smtp");
     final String username = "xxxx@gmail.com";//
     final String password = "0000000";
     try{
     Session session = Session.getDefaultInstance(props, 
                          new Authenticator(){
                             protected PasswordAuthentication getPasswordAuthentication() {
                                return new PasswordAuthentication(username, password);
                             }});

   // -- Create a new message --
     Message msg = new MimeMessage(session);

  // -- Set the FROM and TO fields --
     msg.setFrom(new InternetAddress("xxxx@gmail.com"));
     msg.setRecipients(Message.RecipientType.TO, 
                      InternetAddress.parse("user120@example.com",false));
     msg.setSubject("Hello");
     msg.setText("How are you");
     msg.setSentDate(new Date());
     Transport.send(msg);
     System.out.println("Message sent.");
  }catch (MessagingException e){ System.out.println("Erreur d'envoi, cause: " + e);}
  }

}

It is very clear from your exception that it is trying to connect to localhost and not to 10.101.3.229

exception snippet : Could not connect to SMTP host: localhost, port: 25;

1.) Please check if there are any null check which is setting localhost as default value

2.) After restarting, if it is working fine, then it means that only at first-run, the proper value is been taken from Properties and from next run the value is set to default. So keep the property-object as a singleton one and use it all-over your project

This should not happen. Can you try doing this? Use the system properties and set the property as below:

Properties properties = System.getProperties();
// Setup mail server
properties.setProperty("mail.smtp.host", "10.101.3.229");

And if you have a port associated, then set this as well.

properties.setProperty("mail.smtp.port", "8080");
freeman

Try to set the property when starting JVM, for example, add -Djava.net.preferIPv4Stack=true.

You can't set it when code running, as the java.net just read it when jvm starting.

And about the root cause, this article give some hint: Why do I need java.net.preferIPv4Stack=true only on some windows 7 systems?.

I was also facing the same error. The reason for this is that there is no smtp server on your environment. For creating a fake smtp server I used this fake-smtp.jar file for creating a virtual server and listening to all the requests. If you are facing the same error, I recommend you to use this jar and run it after extracting and then try to run your application.

Download latest version of fake smtp

标签
java
javamail
tomcat5.5
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