“java.net.connectionException” showing connection refused

Question

I am trying to work on java mail api and have the following code in my servlet to sen mail.I cannot find out the way to resolve the error.

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        // Recipient's email ID needs to be mentioned.
          String to = "[email protected]";

          // Sender's email ID needs to be mentioned
          String from = "abc.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);

          // Set response content type
          response.setContentType("text/html");
          PrintWriter out = response.getWriter();

          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
             String subject=request.getParameter("subject");
             String content=request.getParameter("mail");


             message.setSubject(subject);
             // Now set the actual message
             message.setText(content);
             // Send message
             Transport.send(message);
             String title = "Send Email";
             String res = "Sent message successfully....";
             String docType =
             "<!doctype html public \"-//w3c//dtd html 4.0 " +
             "transitional//en\">\n";
             out.println(docType +
             "<html>\n" +
             "<head><title>" + title + "</title></head>\n" +
             "<body bgcolor=\"#f0f0f0\">\n" +
             "<h1 align=\"center\">" + title + "</h1>\n" +
             "<p align=\"center\">" + res + "</p>\n" +
             "</body></html>");
          }catch (MessagingException mex) {
             mex.printStackTrace();
          }

    }

I am getting the following error in my console:

Caused by: java.net.ConnectException: Connection refused: connect at java.net.DualStackPlainSocketImpl.connect0(Native Method) at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source) at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source) at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source) at java.net.AbstractPlainSocketImpl.connect(Unknown Source) at java.net.PlainSocketImpl.connect(Unknown Source) at java.net.SocksSocketImpl.connect(Unknown Source) at java.net.Socket.connect(Unknown Source) at java.net.Socket.connect(Unknown Source) at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:312) at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:236) at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:2019) ... 29 more

String from = "abc.com"; - This is not a valid email address in the first place. — Sandeep Chatterjee

CupawnTae CupawnTae · Accepted Answer · 2014-05-11T08:00:55

You don't have an SMTP server running on localhost, and you are telling the API to use localhost as your mail server.

You either need to install a local SMTP server, or set the smtp hostname to a server you have access to, something like:

      String host = "smtp.yourisp.com"; // real server name required here

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

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

“java.net.connectionException” showing connection refused

2 Answers