title: Could not connect to SMTP host.Java mail Error
body: <p>I am trying to send a mail using java mail API.Here is my code</p>
  
  <pre><code> public static void sendMail(MailObject mail) throws Exception
         {    
  
            String to = mail.toAdress;
            String from = mail.fromName;        
            String host = "mail.mycompanyname.com"; //$NON-NLS-1$
          //  String port="25";
            Properties properties = System.getProperties();        
            properties.setProperty("mail.smtp.host", host); //$NON-NLS-1$
          // properties.setProperty()); //$NON-NLS-1$ //$NON-NLS-2$
            properties.put("mail.smtp.port", "25");
            Session session = Session.getDefaultInstance(properties);
  
             //  MimeMessage message = new MimeMessage(session);
  
              String add = mail.attachmentLocation;
  
               MimeMessage message = new MimeMessage(session);
               message.setSubject(mail.subject);
                // create the message 
                MimeBodyPart messageBodyPart = new MimeBodyPart();
  
                //fill message to be sent
                messageBodyPart.setText(mail.message);
  
                Multipart multipart = new MimeMultipart();
                multipart.addBodyPart(messageBodyPart);
  
                //attach your file here
                messageBodyPart = new MimeBodyPart();
  
                DataSource source =  new FileDataSource(mail.attachmentLocation); // your file
                messageBodyPart.setDataHandler( new DataHandler(source));
                messageBodyPart.setFileName(mail.attachmentName);
                multipart.addBodyPart(messageBodyPart);
  
                // Put message in parts
                message.setContent(multipart);
  
               message.setFrom(new InternetAddress(from));
  
               message.addRecipient(Message.RecipientType.TO,
                                        new InternetAddress(to));
  
  
  
  
               Transport.send(message);
               System.out.println("Sent message successfully...."); //$NON-NLS-1$
  
         }
  class MailObject
  {
  String toAdress;
  String fromName;
  String subject;
  String message;
  String attachmentLocation;
  String attachmentName;
  HTMLPage pageObject;
  }
  </code></pre>
  
  <p>But i am getting Could not connect to smtp server error.Here is the full stack trace</p>
  
  <pre><code>javax.mail.MessagingException: Could not connect to SMTP host: mail.mycompany.com, port: 25;
    nested exception is:
      java.net.SocketException: Network is unreachable: connect
  Could not connect to SMTP host: mail.mycompanyname.com, port: 25
      at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1282)
      at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:370)
      at javax.mail.Service.connect(Service.java:275)
      at javax.mail.Service.connect(Service.java:156)
      at javax.mail.Service.connect(Service.java:105)
      at javax.mail.Transport.send0(Transport.java:168)
      at javax.mail.Transport.send(Transport.java:98)
      at MailManager.sendMail(MailManager.java:68)
      at MailManager$1.widgetSelected(MailManager.java:122)
      at org.eclipse.swt.widgets.TypedListener.handleEvent(Unknown Source)
      at org.eclipse.swt.widgets.EventTable.sendEvent(Unknown Source)
      at org.eclipse.swt.widgets.Display.sendEvent(Unknown Source)
      at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
      at org.eclipse.swt.widgets.Display.runDeferredEvents(Unknown Source)
      at org.eclipse.swt.widgets.Display.readAndDispatch(Unknown Source)
      at MailManager.openMailDialogue(MailManager.java:165)
      at App2$2.widgetSelected(App2.java:311)
      at org.eclipse.swt.widgets.TypedListener.handleEvent(Unknown Source)
      at org.eclipse.swt.widgets.EventTable.sendEvent(Unknown Source)
      at org.eclipse.swt.widgets.Display.sendEvent(Unknown Source)
      at org.eclipse.swt.widgets.Widget.sendEvent(Unknown Source)
      at org.eclipse.swt.widgets.Display.runDeferredEvents(Unknown Source)
      at org.eclipse.swt.widgets.Display.readAndDispatch(Unknown Source)
      at App2.main(App2.java:521)
  Caused by: java.net.SocketException: Network is unreachable: 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:232)
      at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:189)
      at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1250)
      ... 23 more
  </code></pre>
  
  <p>i have tried to ping the server using telnet and it showed me the welcome screen.</p>