SMTP: Transport.send() works, transport.sendMessage() not ("not connected")

Question

Sendig a SMTP Message to a running SMTP Server on localhost, port 25 works fine, if i use
Transport.send( myMessage);However, it does not when i use
Transport tr = session.getTransport(..);
tr.connect("localhost", 25, "user", "pass");
tr.sendMessage ( myMessage );In this case, the connect seems to work (actually, debugging in eclipse has shown that the Transport-internal field "connected" is set to true!), but sending myMessage throws the following Exception:
java.lang.IllegalStateException: Not connected
     at com.sun.mail.smtp.SMTPTransport.checkConnected SMTPTransport.java:1398)
     at com.sun.mail.smtp.SMTPTransport.sendMessage SMTPTransport.java:489)calling transport.isConnected() also returnsfalseWell, using the static way is a first workaround, that i don't want to use because of the bad performance (need to send lot of mails under certain circumstances).
Does anyone have an idea whats wrong?

Answer 1

If your SMTP server does not require authentication, do not use "Transport.connect(server, port, username, password)", use "Transport.connect()" instead.
If you SMTP server does require authentication, you should have the "mail.smtp.auth" property of the session set as "true".
The following code is working properly on my machine.
import java.lang.*;
import java.util.*;
import javax.mail.*;
import javax.mail.event.*;
import javax.mail.internet.*;
public class SendMail {
static String mailHost = "mail.mydomain.com";
static String source = "[email protected]";
static String subject = "Test JavaMail";
static String content = "Content";
public static void main(String args[]) {
Properties properties = new Properties();
properties.put("mail.smtp.host", mailHost);
properties.put("mail.from", source);
Session session = Session.getInstance(properties, null);
try {
Message message = new MimeMessage(session);
InternetAddress[] address = new InternetAddress[args.length];
for (int i = 0; i < args.length; i++)
address[i] = new InternetAddress(args);
message.setRecipients(Message.RecipientType.TO, address);
message.setFrom(new InternetAddress(source));
message.setSubject(subject);
message.setContent(content, "text/plain");
Transport transport = session.getTransport(address[0]);
transport.addConnectionListener(new ConnectionHandler());
transport.addTransportListener(new TransportHandler());
transport.connect();
transport.sendMessage(message, address);
} catch (Exception e) {
System.out.println(e.toString());
class ConnectionHandler extends ConnectionAdapter {
public void opened(ConnectionEvent e) {
System.out.println("Connection opened.");
public void disconnected(ConnectionEvent e) {
System.out.println("Connection disconnected.");
public void closed(ConnectionEvent e) {
System.out.println("Connection closed.");
class TransportHandler extends TransportAdapter {
public void messageDelivered(TransportEvent e) {
System.out.println("Message delivered.");
public void messageNotDelivered(TransportEvent e) {
System.out.println("Message NOT delivered.");
public void messagePartialDelivered(TransportEvent e) {
System.out.println("Message partially delivered.");