来自 Java 程序的电子邮件不起作用

Question

I wrote a java program for sending email using my company's email server. The code snippet below:

      Properties props = System.getProperties();
      props.put("mail.smtps.host", "mail.xxx.com");
      props.put("mail.smtps.auth", "true");
      props.put("mail.smtps.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
      props.put("mail.smtps.port", "888");
      props.put("mail.smtp.starttls.enable","true");
      Session session =
      Session.getInstance(props, null); Message msg = new
      MimeMessage(session); msg.setFrom(new
      InternetAddress("yyy@mydomain.com"));
      msg.setRecipients(Message.RecipientType.TO,
      InternetAddress.parse("yyy@mydomain.com", false));
      msg.setSubject("Good Morning " + System.currentTimeMillis());
      msg.setText("This is for Test"); 
      msg.setHeader("X-Mailer", "My program"); 
      msg.setSentDate(new Date()); 
      SMTPTransport t = (SMTPTransport) session.getTransport("smtps");
      t.connect("mail.xxx.com", "yyy@mydomain.com", "myPwd");
      t.sendMessage(msg, msg.getAllRecipients());
      System.out.println("Response: " + t.getLastServerResponse());
      t.close();

The email functionality is not working. Getting the following error:

Exception in thread "main" javax.mail.MessagingException: Could not connect to SMTP host: mail.xxx.com, port: 888;
  nested exception is:
    java.net.ConnectException: Connection refused: connect
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1972)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:642)
    at javax.mail.Service.connect(Service.java:295)
    at javax.mail.Service.connect(Service.java:176)
    at cab.mail.Distribution.main(Distribution.java:50)
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:319)
    at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:233)
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1938)
    ... 4 more

Would like to know what is causing the problem. I tested this code with gmail server and my personal gmail id, it works fine. Could not figure out what I am missing over here.

Answer 1

The root cause:

Caused by: java.net.ConnectException: Connection refused: connect

Make sure that your application has access to your mail server mail.xxx.com at port 888 and make sure that your port is open at the firewall.

Answer 2

Some antivirus (for example ViruScan) by default allows SMTP only to selected programs (like Outlook) and its white-list doesn't include Java. Check your antivirus settings. And, of course, also your firewall settings as suggested in another answer.