EMail program Java-Connection

[Comal Rajagopalaratnam Muthukumar]

Hi
I tried to send a message through  Java Created EmailProgram  But
the connection is to be obtaiiined as you can see the following error
Please help
Thanks
As
CRMK




**********************************************
[code]
Exception in thread "main" java.net.ConnectException: Connection refused: connec
t
       at java.net.DualStackPlainSocketImpl.connect0(Native Method)
       at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketI
mpl.java:79)
       at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.ja
va:350)
       at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocket
Impl.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 java.net.Socket.<init>(Socket.java:434)
       at java.net.Socket.<init>(Socket.java:211)
       at MailMessage.connect(MailMessage.java:280)
       at MailMessage.<init>(MailMessage.java:110)
       at MailMessage.main(MailMessage.java:370)
*****************************************
[/code}

[Pete Letkeman]

There are a few too many unknowns at this point in time so maybe you can answer a few questions?

Connection refused could be because the email server that you are using did not like you trying to connect at that point in time. Are you 100% that the email server is working as correctly?

Are you sure that the account which you are using to connect to the mail server is a valid account?

Are you able to provide us with the code that is connecting to the email server?

Are you able to provide us with the code that is trying to send out the email message?

It can be helpful to the rest of us if you use the codetags (https://coderanch.com/wiki/659781/Code-Tags) and good indentation when posting code.
It can be helpful to use the Preview button, which is just left of the Submit button to verify that your post looks proper and sound the way you want it to.
I use the Preview button all of the time, which helps me cut down on mistakes.

[Matt Wong]

Hi Comal,
as I'm a bit more into the whole topic about java and e-mail I can give you some input:

It seems you're tryin to connect to the server directly instead of use java mail api. I recommend you to use it. It handles many things for you so you don't have to speak smtp to the target server directly.
So I guess your code some looks some like this:

public final class MailMessage
{
	private final SERVER="smtp.example.invalid";
	prviate final int PORT=25/465/587;
	public final static void main(final String... args)
	{
		MailMessage instance=new MailMessage();
		instance.connect();
	}
	private MailMessage() { }
	private final void connect()
	{
		Socket socket=new Socket(SERVER, PORT); //this line throws the exception
	}
}

Rather strange your Source is over 370 lines long but the very basics doesn't work.

There're a couple of reasons the connection is refused:

- You're tryin to directly connect to the target SMTP server - and maybe this connection gets refused cause the server only accepts connections from other "registered" SMTP servers but refuses connections from private IP ranges - simple spam protection.
- If you're try to connect to a SMTP server of your mail provider - you maybe try to connect to the wrong port. A SMTP server usualy has following ports opened:
TCP/25 - to receive mails from other SMTP servers - normaly plain unencrypted - but could also provide STARTTLS feature
TCP/465 - to accept mail-submission from registered clients - secured by socket level TLS
TCP/587 - same as above - but mostly used with STARTTLS command instead of socket level TLS

Here's a sample:

package mail;
import java.util.*;
import javax.mail.*;
import javax.mail.internet.*;
public class SendMailTLS2
{
	public static void main(String[] args) throws Exception
	{
		String host="mail.example.invalid";
		int port=587;
		String user="[e-mail]";
		String pass="securepassword";

		Properties props=new Properties();
		props.put("mail.smtp.starttls.enable", "true");

		Session session=Session.getInstance(props);
		Transport transport=session.getTransport("smtp");
		transport.connect(host, port, user, pass);

		Address[] addresses=InternetAddress.parse("[e-mail]");

		Message message=new MimeMessage(session);
		message.setFrom(new InternetAddress(user));
		message.setRecipients(Message.RecipientType.TO, addresses);
		message.setSubject("subject");

		MimeMultipart multipart=new MimeMultipart();

		MimeBodyPart bodypart=new MimeBodyPart();
		bodypart.setText("plain text");
		multipart.addBodyPart(bodypart);

		message.setContent(multipart);

		transport.sendMessage(message, addresses);

		transport.close();
	}
}

Obviously you need java mail api in your classpath to compile and run.
Try to get my sample working - and post stacktraces if you encounter exceptions so we can narrow down the problem.

Hope it helps in any way.

Matt

[Comal Rajagopalaratnam Muthukumar]

Matt Wong wrote:Hi Comal,
as I'm a bit more into the whole topic about java and e-mail I can give you some input:

It seems you're tryin to connect to the server directly instead of use java mail api. I recommend you to use it. It handles many things for you so you don't have to speak smtp to the target server directly.
So I guess your code some looks some like this:

public final class MailMessage
{
	private final SERVER="smtp.example.invalid";
	prviate final int PORT=25/465/587;
	public final static void main(final String... args)
	{
		MailMessage instance=new MailMessage();
		instance.connect();
	}
	private MailMessage() { }
	private final void connect()
	{
		Socket socket=new Socket(SERVER, PORT); //this line throws the exception
	}
}

Rather strange your Source is over 370 lines long but the very basics doesn't work.

There're a couple of reasons the connection is refused:

- You're tryin to directly connect to the target SMTP server - and maybe this connection gets refused cause the server only accepts connections from other "registered" SMTP servers but refuses connections from private IP ranges - simple spam protection.
- If you're try to connect to a SMTP server of your mail provider - you maybe try to connect to the wrong port. A SMTP server usualy has following ports opened:
TCP/25 - to receive mails from other SMTP servers - normaly plain unencrypted - but could also provide STARTTLS feature
TCP/465 - to accept mail-submission from registered clients - secured by socket level TLS
TCP/587 - same as above - but mostly used with STARTTLS command instead of socket level TLS

Here's a sample:

package mail;
import java.util.*;
import javax.mail.*;
import javax.mail.internet.*;
public class SendMailTLS2
{
	public static void main(String[] args) throws Exception
	{
		String host="mail.example.invalid";
		int port=587;
		String user="[e-mail]";
		String pass="securepassword";

		Properties props=new Properties();
		props.put("mail.smtp.starttls.enable", "true");

		Session session=Session.getInstance(props);
		Transport transport=session.getTransport("smtp");
		transport.connect(host, port, user, pass);

		Address[] addresses=InternetAddress.parse("[e-mail]");

		Message message=new MimeMessage(session);
		message.setFrom(new InternetAddress(user));
		message.setRecipients(Message.RecipientType.TO, addresses);
		message.setSubject("subject");

		MimeMultipart multipart=new MimeMultipart();

		MimeBodyPart bodypart=new MimeBodyPart();
		bodypart.setText("plain text");
		multipart.addBodyPart(bodypart);

		message.setContent(multipart);

		transport.sendMessage(message, addresses);

		transport.close();
	}
}

Obviously you need java mail api in your classpath to compile and run.
Try to get my sample working - and post stacktraces if you encounter exceptions so we can narrow down the problem.

Hope it helps in any way.

Matt

Hi
Thanks.However
I shall try to use the code  as suggested .
But very importantly the input should be via stream data
for easy functioning that i have shown below.please suggest alter native if socket usage may be cause for error like  connection
refusal erc
As
CRMK

*******************************************
import java.io.*;
import java.net.*;
import java.util.*;
************************************
(Raw Protocool code)
public MailMessage() throws IOException {
    this("localhost");
  }
void connect() throws IOException {
    socket = new Socket(host, 25);
    out = new MailPrintStream(
          new BufferedOutputStream(
          socket.getOutputStream())); 
    in = new BufferedReader(
      new InputStreamReader(socket.getInputStream(), "ISO-8859-1")); 
    getReady();
  }
********************************************

[Matt Wong]

Well, I wouldn't try to implement raw smtp by myself - use java mail lib instead.
Did you tried to telnet localhost:25 ?
This might work on a linux machine as usual there should be a mail deamon runnung - but on windows you have to setup a mail server first as windows doesn't have any MTA pre-installed.
Anyway: we still need some more information to help you.

[Comal Rajagopalaratnam Muthukumar]

Matt Wong wrote:Well, I wouldn't try to implement raw smtp by myself - use java mail lib instead.
Did you tried to telnet localhost:25 ?
This might work on a linux machine as usual there should be a mail deamon runnung - but on windows you have to setup a mail server first as windows doesn't have any MTA pre-installed.
Anyway: we still need some more information to help you.

Hi
Thanks.
The following codes are shown just randomly to indicate
the use of data gramsocket
But this is a different prg .Howere contexrually it might help as to port
selection is rather difficult as said by you
This is for your perusal
Also sample.png enclosed
As
CRMK
***********************************

class StationChosen implements ActionListener{
                 public void actionPerformed(ActionEvent ae){
                 if (ae.getSource()==ok) {
               String station = stationList.getSelectedItem();
                 setTitle("attempting to connect ... "+station);
                    frm.setTitle("attempting to connect ... " +station);
                   frm.setHostName(station);
               frm.sendMessage(MessageConstants.TEST +" ");
                while(!frm.outOfWhileLoop);
                if(frm.getReceived()==true){
                     frm.setHostName(station);
                      setTitle("Chat: connected to "+station);
                      frm.setTitle("Chat :connected to"+station);
                    setVisible(true);
                   //  setVisible(false);

                     frm.setVisible(true);
                }
             else{
                  frm.setTitle("chat:  "+station+ "not responding!");
                       setTitle("chat: "+station +"not responding!");
                }
              }
           }
        }
         class ServerWindow extends Frame implements MessageConstants,Runnable{
	             static int clientport1=555,serverport1=1001;
	             static byte b[]=new byte[512];
	             static DatagramSocket ds1;
	              static DatagramPacket dp;
	              Thread ackThread;
	               String hostName;
	               String fileName=null;
	               TextArea taSend;
	               TextArea taReceive;
	               Button  sendButton;
	               Button receiveButton;
               Button ClearButton;
        ******************************************
      StationListFrame(ServerWindow frm){
	                     super("connected to ntw2");
	                }
	                

[Comal Rajagopalaratnam Muthukumar]

Matt Wong wrote:Well, I wouldn't try to implement raw smtp by myself - use java mail lib instead.
Did you tried to telnet localhost:25 ?
This might work on a linux machine as usual there should be a mail deamon runnung - but on windows you have to setup a mail server first as windows doesn't have any MTA pre-installed.
Anyway: we still need some more information to help you.

Hi
On same lines
the prg  (from java3)on execution,produces a minor error though it started connecting
this time
as shown
Shall be thankfull if the error  for  (mail-host) substituted with a suitable  alternative .
I tried local host but invain

Thanks
As
CRMK

try {
            // If the user specified a mailhost, tell the system about it.
            if (args.length >= 1)
		System.getProperties().put("maill.host", args[0]);
	    
            // A Reader stream to read from the console
            BufferedReader in =new BufferedReader(new InputStreamReader(System.in));
	   Connecting...
java.net.UnknownHostException: mailhost
        at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java
:184)
        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 sun.net.NetworkClient.doConnect(NetworkClient.java:180)
        at sun.net.NetworkClient.openServer(NetworkClient.java:136)
        at sun.net.smtp.SmtpClient.openServer(SmtpClient.java:128)
        at sun.net.smtp.SmtpClient.<init>(SmtpClient.java:200)
        at sun.net.www.protocol.mailto.MailToURLConnection.connect(MailToURLConn
ection.java:86)
        at je3.net.SendMail.main(SendMail.java:43)
        

[Matt Wong]

Sorry, but your posts some get more and more away from your initial question I don't know what you're try to say or ask anymore.
I've replied to your question why you get a connection reset with a few guesses and ask you to provide us some more information. But unfortunatly your last two posts doesn't help as they don't seem to relate to your initial problem.
If you're still asking for some help please try to re-order your question and additional code so we can follow up again.

[Comal Rajagopalaratnam Muthukumar]

Matt Wong wrote:Hi Comal,
as I'm a bit more into the whole topic about java and e-mail I can give you some input:
It seems you're tryin to connect to the server directly instead of use java mail api. I recommend you to use it. It handles many things for you so you don't have to speak smtp to the target server directly.
Matt

Hi
 In fact I tried three programs in  java  to forwatd a sample meesaege. but none of them gave fruitful result. inlieu
 of the follwing points
 
 !)MailMessage that was having connection problem and complicated with lmore line of code
  2)ServerFrame.java -->that was a j-chat. software in GUI environment,acknowledging  Datagram Service
   requiring different systems of network
 3)Send Mail.java  the  third one supposed to be easy but hardly this also had problem
 
 Since you seem to inform about your  rich comprehension about this topic,
 
 i  did show  all of these to get any one  prg cleared atlleast Also i am not well versed in certian nomenclature used in prgs
 So please help me if  you can make  the follwing prg  error free
 Hope this suffices for a favourable  solution
 Thanks
 As
 CRMK
   

  package je3.net;
  import java.io.*;
  import java.net.*;
  
  /**
   * This program sends e-mail using a mailto: URL
   **/
  public class SendMail {
      public static void main(String[] args) {
          try {
              // If the user specified a mailhost, tell the system about it.
              if (args.length >= 1)
  		System.getProperties().put("maill.host", args[0]);
  	    
              // A Reader stream to read from the console
              BufferedReader in =new BufferedReader(new InputStreamReader(System.in));
  	     // Ask the user for the from, to, and subject lines
              System.out.print("From: ");
              String from = in.readLine();
              System.out.print("To: ");
              String to = in.readLine();
              System.out.print("Subject: ");
              String subject = in.readLine();
  	    
              // Establish a network connection for sending mail
              URL u = new URL("mailto:" + to);      // Create a mailto: URL 
              URLConnection c = u.openConnection(); // Create its URLConnection
              c.setDoInput(false);                  // Specify no input from it
              c.setDoOutput(true);                  // Specify we'll do output
              System.out.println("Connecting...");  // Tell the user
              System.out.flush();                   // Tell them right now
              c.connect();                          // Connect to mail host
              PrintWriter out =                     // Get output stream to host
                  new PrintWriter(new OutputStreamWriter(c.getOutputStream()));
  
  	    // We're talking to the SMTP server now.
              // Write out mail headers.  Don't let users fake the From address
              out.print("From: \"" + from + "\" <" +
  		      System.getProperty("user.name") + "@" + 
  		      InetAddress.getLocalHost().getHostName() + ">\r\n");
              out.print("To: " + to + "\r\n");
              out.print("Subject: " + subject + "\r\n");
              out.print("\r\n");  // blank line to end the list of headers
  
              // Now ask the user to enter the body of the message
              System.out.println("Enter the message. " + 
  			       "End with a '.' on a line by itself.");
              // Read message line by line and send it out.
              String line;
              for(;;) {
                  line = in.readLine();
                  if ((line == null) || line.equals(".")) break;
                  out.print(line + "\r\n");
              }
  	    
              // Close (and flush) the stream to terminate the message 
              out.close();
              // Tell the user it was successfully sent.
              System.out.println("Message sent.");
          }
          catch (Exception e) {  // Handle any exceptions, print error message.
              e.printStackTrace();
             // System.err.println(e);
             // System.err.println("Usage: java SendMail [<mailhost>]");
          }
      }
  }

 

[Comal Rajagopalaratnam Muthukumar]

Matt Wong wrote:Well, I wouldn't try to implement raw smtp by myself - use java mail lib instead.
Did you tried to telnet localhost:25 ?
This might work on a linux machine as usual there should be a mail deamon runnung - but on windows you have to setup a mail server first as windows doesn't have any MTA pre-installed.
Anyway: we still need some more information to help you.

Hi
Please correct the prg(email)  for sending the trailer message.


Thanks
As
CRMK