发送邮件错误，javax.mail.MessagingException：无法连接到SMTP主机：localhost，port：25;

Here is my code

这是我的代码

import java.util.Properties;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;


public class MailSendClass {
    public static void main (String [] args){

      // Recipient's email ID needs to be mentioned.
      String to = "abc82@gmail.com";

      // Sender's email ID needs to be mentioned
      String from = "xyz@gmail.com";

      // 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("Thanks for registering on our website!");

         // Now set the actual message
         message.setText("Welcome To Job Portal !!!!  Again Thanks ");

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

    }
}

And I am getting this error everytime

我每次都会收到这个错误

javax.mail.MessagingException: Could not connect to SMTP host: localhost, port: 25;
  nested exception is:
    java.net.ConnectException: Connection refused: connect
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1706)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:525)
    at javax.mail.Service.connect(Service.java:291)
    at javax.mail.Service.connect(Service.java:172)
    at javax.mail.Service.connect(Service.java:121)
    at javax.mail.Transport.send0(Transport.java:190)
    at javax.mail.Transport.send(Transport.java:120)
    at MailSendClass.main(MailSendClass.java:58)
Caused by: java.net.ConnectException: Connection refused: connect
    at java.net.DualStackPlainSocketImpl.connect0(Native Method)
    at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:345)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    at java.net.Socket.connect(Socket.java:589)
    at java.net.Socket.connect(Socket.java:538)
    at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:284)
    at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:227)
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1672)
    ... 7 more
BUILD SUCCESSFUL (total time: 3 seconds)

I am not getting the error why this is happening. Please help me in fixing this error.

我没有收到错误,为什么会发生这种情况。请帮我修复此错误。

4 个解决方案

#1

Error is self explainatory: javax.mail.MessagingException: Could not connect to SMTP host: localhost, port: 25;

错误是自解释的:javax.mail.MessagingException:无法连接到SMTP主机:localhost,port:25;

You have no SMTP server on localhost, but you configure it there :

您在localhost上没有SMTP服务器,但是在那里配置它:

  // Assuming you are sending email from localhost
  String host = "localhost";
  ...
  // Setup mail server
  properties.setProperty("mail.smtp.host", host);

So you must:

所以你必须:

either configure a local SMTP server as a relay on your local system (Postfix or sendmail are two well knows servers)

将本地SMTP服务器配置为本地系统上的中继(Postfix或sendmail是两个知道的服务器)

of configure a dummy server that simply traces the mail request but does not even try to deliver mail (Python is known to have such dummy servers out of the box)

配置虚拟服务器,只是跟踪邮件请求,但甚至没有尝试传递邮件(已知Python有这样的虚拟服务器开箱即用)

or configure your application with a server that you are allowed to use - contact your system admin in a corporate environment, or your ISP in an individual one. Anyway, you will need that even to configure a true relay.

或者使用您可以使用的服务器配置您的应用程序 - 在公司环境中联系您的系统管理员,或在单个ISP中联系您的ISP。无论如何,你甚至需要配置一个真正的中继。

#2

You should use the free Google SMTP server as a test.

您应该使用免费的Google SMTP服务器作为测试。

mail.host=smtp.gmail.com
mail.username=//your gmail
mail.password=//your password
mail.defaultEncoding=UTF-8
mail.smtp.auth=true
mail.smtp.starttls.required=true
mail.smtp.starttls.enable=true
mail.smtp.socketFactory.class=javax.net.ssl.SSLSocketFactory
mail.smtp.socketFactory.fallback=false
mail.smtp.port=465
mail.smtp.socketFactory.port=465

Next, login with your gmail , and turn on less secure apps.

接下来,使用您的Gmail登录,并打开不太安全的应用程序。

#3

You should look at this two lines:

你应该看看这两行:

javax.mail.MessagingException: Could not connect to SMTP host: localhost, port: 25;
Caused by: java.net.ConnectException: Connection refused: connect

The error is: "There is nothing listening on localhost at port 25".

错误是:“没有任何东西在端口25上侦听localhost”。

You are trying to use localhost:25 as mail server, but there is no server there.

您正在尝试使用localhost:25作为邮件服务器,但那里没有服务器。

#4

Here is the working solution bro. it's guranteed

这是工作解决方案兄弟。这是保证

1) First of all open your gmail account from which you wanted to send mail, like in you case ""xyz@gmail.com"

1)首先打开您要发送邮件的Gmail帐户,例如“xyz@gmail.com”

2) open this link below https://support.google.com/accounts/answer/6010255?hl=en

2)打开https://support.google.com/accounts/answer/6010255?hl=en下面的链接

3) click on "Go to the "Less secure apps" section in My Account." option

3)点击“转到我的帐户中的”安全性较低的应用“部分。”选项

4) Then turn on it

4)然后打开它

5) that's it (:

5)就是这样(:

#1