无法使用JavaMail发送任何邮件

Question

我想用Java发送一封邮件，但使用我在http://www.tutorialspoint.com/Java/java_sending_email.htm找到的这篇泰文教程是行不通的。

这里是我的主要方法

public static void main(String[] args) {
        // Recipient's email ID needs to be mentioned.
      String to = "[e-mail]";

      // Sender's email ID needs to be mentioned
      String from = "[e-mail]";

      // Assuming you are sending email from localhost
      String host = "localhost";

      // Get system properties
      Properties properties = System.getProperties();

      // Setup mail server
      properties.setProperty("smtp.laposte.net", host);

      // Get the default Session object.
      Session session = Session.getDefaultInstance(properties);

      try{
         // Create a default MimeMessage object.
         MimeMessage message = new MimeMessage(session);

         // Set From: header field of the header.
         message.setFrom(new InternetAddress(from));

         // Set To: header field of the header.
         message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));

         // Set Subject: header field
         message.setSubject("This is the Subject Line!");

         // Now set the actual message
         message.setText("This is actual message");

         // Send message
         Transport.send(message);
         System.out.println("Sent message successfully....");
      }catch (MessagingException mex) {
         mex.printStackTrace();
      }
    }

我有以下错误：

javax.mail.MessagingException：无法连接到SMTP主机：localhost，端口：25；嵌套异常为：java.net.connectException：连接被拒绝：在com.sun.mail.smtp.smtptransport.openserver（smtptransport.java:1972)在com.sun.mail.smtp.smtptransport.protocolconnect（smtptransport.java:1972)在com.sun.mail.smtp.smtptransport.protocolconnect（smtptransport.java:642)在javax.mail.service.connect（service.java:295)在javax.mail.service.connect（service.java:295)在javax.mail.service.connect（service.java:176)在javax.mail.service.connect（原因：java.net.ConnectException：连接被拒绝：java.net.DualStackPlainSockeTimpl.Connect0（本机方法）java.net.DualStackPlainSockeTimpl.SocketConnect（DualStackPlainSockeTimpl.java:79)java.net.AbstractPlainSockeTimpl.DoConnect（AbstractPlainSockeTimpl.350）java.net.AbstractPlainSockeTimpl.ConnectToAddress（AbstractPlainSockeTimpl.206）java.net.AbstractPlainSockeTimpl.connect（AbstractPlainSockeTimpl.188）t(plainsockeTimpl.java:172)在java.net.socksockeTimpl.connect（socksockeTimpl.java:392)在java.net.socket.connect（socket.java:589)在java.net.socket.connect（socket.java:538)在com.sun.mail.util.socketfetcher.createSocket（socketfetcher.java:319)在com.sun.mail.util.socketfetcher.getsocket（socketfetcher.java:233)在com.sun.mail.smtp.smtptransport.openserver（smtptransport.java:1938)...7个生成成功（总时间

Answer 1

主机使用时出错

host="smtp.gmail.com";