通过Java发送邮件时出错 [英] Error in Sending mail by Java

问题描述

我的代码是:

// File Name SendEmail.java

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

public class SendEmail
{
   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("mail.smtp.host", 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();
      }
   }
}

昨晚我的程序运行正常；我可以将电子邮件从任何地址发送到任何其他地址，但是现在出现此错误:

My program was working correctly last night; I could send email from any address to any other, but now this error is occuring:

javax.mail.SendFailedException: Sending failed;
  nested exception is:
    class javax.mail.MessagingException: Could not connect to SMTP host: localhost, port: 25;
  nested exception is:
    java.net.ConnectException: Connection refused
    at javax.mail.Transport.send0(Transport.java:218)
    at javax.mail.Transport.send(Transport.java:80)
    at SendEmail.main(SendEmail.java:49)

第49行是:

Transport.send(message);

有人可以帮我解决此错误吗?

Can anyone help me fix this error?

我的操作系统是:Linux，Fedora 16-内核:3.3.7

My operating system is : Linux,Fedora 16 -kernel: 3.3.7

推荐答案

无法连接到SMTP主机:localhost，端口:25;

SMTP必须未在系统上运行或作为用户禁用.请与系统管理员联系，并为您启用它.

SMTP must be not running on your system or disabled for you as user. Check with your system administrator and get it enabled for you.

要检查SMTP是否在您的Linux系统上正常运行，请尝试以下命令:

To check if SMTP is working on your Linux system, try the following commands:

1. 要简单地验证Sendmail是否正在运行，请尝试:netstat -an | grep 25
2. 使用telnet连接到smtp服务器的端口25:telnet <yourhost-or-ipnumber> 25
   一种. 连接到本地主机...无法打开端口25上的主机连接:连接失败.
   b.如果您或您的IP被阻止，则会看到类似以下错误消息:
   220-localhost ESMTP Exim 4.63#1 Fri，01 Jun 2012 19:35:30 +0530
   220-我们未经授权使用此系统来传输未经请求的和/或批量电子邮件.
3. echo -e "quit" | nc localhost 25
   localhost.localdomain [127.0.0.1] 25(?):连接被拒绝
在外壳程序提示符下
4. 邮件.
5. 还有，可能更多...

1. To simply verify Sendmail is running, try: netstat -an | grep 25
2. Use telnet to connect to port 25 of smtp server: telnet <yourhost-or-ipnumber> 25
   a. Connecting To localhost...Could not open connection to the host, on port 25: Connect failed.
   b. if you or your ip is blocked, you would see error message something like this:
   220-localhost ESMTP Exim 4.63 #1 Fri, 01 Jun 2012 19:35:30 +0530
   220-We do not authorize the use of this system to transport unsolicited, and/or bulk e-mail.
3. echo -e "quit" | nc localhost 25
   localhost.localdomain [127.0.0.1] 25 (?) : Connection refused
4. mail at shell prompt.
5. and, may be more...

您应检查sendmail守护程序是否已启动并且始终可用.

You should check that sendmail daemon is started and is available always.

如果您有权访问其他任何SMTP服务器，请尝试使用其SMTP主机名发送邮件，以检查您的代码段是否正常工作.
示例:String host = "smtp.gmail.com";

And if you have access to any other SMTP servers, try to send mail using their SMTP host name, to check if your code snippet is working.
Example : String host = "smtp.gmail.com";

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