Question

I am trying to send Email using java mail API from with in a proxy server. The code is as follows:

import java.security.Security;
import java.util.Date;
import java.util.Properties;
import javax.mail.Authenticator;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.AddressException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;


public class GmailSender {

public static void main(String[] args) throws AddressException, MessagingException {


Security.addProvider(new com.sun.net.ssl.internal.ssl.Provider());
final String SSL_FACTORY = "javax.net.ssl.SSLSocketFactory";
// Get a Properties object
Properties props = System.getProperties();
props.setProperty("proxySet","true");
props.setProperty("socksProxyHost","192.168.1.103");
props.setProperty("socksProxyPort","3128");
props.setProperty("mail.smtp.host", "smtp.gmail.com");
props.setProperty("mail.smtp.socketFactory.class", SSL_FACTORY);
props.setProperty("mail.smtp.socketFactory.fallback", "false");
props.setProperty("mail.smtp.port", "465");

props.setProperty("mail.smtp.socketFactory.port", "465");
props.put("mail.smtp.auth", "true");
props.put("mail.debug", "true");
props.put("mail.store.protocol", "pop3");
props.put("mail.transport.protocol", "smtp");
final String username = "proxy_userName";
final String password = "proxy_password";
Session session = Session.getDefaultInstance(props,
new Authenticator(){
protected PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication(username, password);
}});

// -- Create a new message --
Message msg = new MimeMessage(session);

// -- Set the FROM and TO fields --
msg.setFrom(new InternetAddress("[e-mail]"));
msg.setRecipients(Message.RecipientType.TO,
InternetAddress.parse("[e-mail]",false));
msg.setSubject("Hello");
msg.setText("How are you");
msg.setSentDate(new Date());
Transport.send(msg);
System.out.println("Message sent.");
}
}

when I run this code following message is displayed.

DEBUG: JavaMail version 1.4.3
DEBUG: successfully loaded resource: /META-INF/javamail.default.providers
DEBUG: Tables of loaded providers
DEBUG: Providers Listed By Class Name: {com.sun.mail.smtp.SMTPSSLTransport=javax.mail.Provider[TRANSPORT,smtps,com.sun.mail.smtp.S    MTPSSLTransport,Sun Microsystems, Inc],  com.sun.mail.smtp.SMTPTransport=javax.mail.Provider[TRANSPORT,smtp,com.sun.mail.smtp.SMTPTr    ansport,Sun Microsystems, Inc],   com.sun.mail.imap.IMAPSSLStore=javax.mail.Provider[STORE,imaps,com.sun.mail.imap.IMAPSSLSto    re,Sun Microsystems, Inc],  com.sun.mail.pop3.POP3SSLStore=javax.mail.Provider[STORE,pop3s,com.sun.mail.pop3.POP3SSLSto    re,Sun Microsystems, Inc],  com.sun.mail.imap.IMAPStore=javax.mail.Provider[STORE,imap,com.sun.mail.imap.IMAPStore,Sun     Microsystems, Inc],  com.sun.mail.pop3.POP3Store=javax.mail.Provider[STORE,pop3,com.sun.mail.pop3.POP3Store,Sun     Microsystems, Inc]}
DEBUG: Providers Listed By Protocol:  {imaps=javax.mail.Provider[STORE,imaps,com.sun.mail.imap.IMAPSSLStore,Sun Microsystems,  Inc], imap=javax.mail.Provider[STORE,imap,com.sun.mail.imap.IMAPStore,Sun Microsystems,  Inc], smtps=javax.mail.Provider[TRANSPORT,smtps,com.sun.mail.smtp.SMTPSSLTransport,Sun  Microsystems, Inc], pop3=javax.mail.Provider[STORE,pop3,com.sun.mail.pop3.POP3Store,Sun  Microsystems, Inc],  pop3s=javax.mail.Provider[STORE,pop3s,com.sun.mail.pop3.POP3SSLStore,Sun Microsystems,  Inc], smtp=javax.mail.Provider[TRANSPORT,smtp,com.sun.mail.smtp.SMTPTransport,Sun  Microsystems, Inc]}
DEBUG: successfully loaded resource: /META-INF/javamail.default.address.map
DEBUG: getProvider() returning   javax.mail.Provider[TRANSPORT,smtp,com.sun.mail.smtp.SMTPTransport,Sun Microsystems, Inc]
DEBUG SMTP: useEhlo true, useAuth true
DEBUG SMTP: useEhlo true, useAuth true
DEBUG SMTP: trying to connect to host "smtp.gmail.com", port 465, isSSL false
Exception in thread "main" javax.mail.MessagingException: Could not connect to SMTP  host: smtp.gmail.com, port: 465;
  nested exception is:
    java.io.IOException: Couldn't connect using unknown socket factory to host, port: smtp.gmail.com, -1; Exception: java.lang.ClassNotFoundException: false
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1706)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:525)
    at javax.mail.Service.connect(Service.java:313)
    at javax.mail.Service.connect(Service.java:172)
    at javax.mail.Service.connect(Service.java:121)
    at javax.mail.Transport.send0(Transport.java:190)
    at javax.mail.Transport.send(Transport.java:120)
    at GmailSender.main(GmailSender.java:57)
Caused by: java.io.IOException: Couldn't connect using unknown socket factory to host,  port: smtp.gmail.com, -1; Exception: java.lang.ClassNotFoundException: false
    at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:216)
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1672)
    ... 7 more
Caused by: java.lang.ClassNotFoundException: false
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Unknown Source)
    at com.sun.mail.util.SocketFetcher.getSocketFactory(SocketFetcher.java:322)
    at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:187)
    ... 8 more

May be the problem is due to the presence of the proxy server. However I could send the mails by logging in to gmail using browser from with in same proxy server.

Kindly suggest as why the programmatic method is failing and the browser method is working.

I would be thankful for any help.

Answer 1

As described in the FAQ, JavaMail can’t use a web proxy server directly, although it can use a SOCKS proxy server. If you only have a web proxy server, programs like Corkscrew can help.

Also, see the JavaMail FAQ for the several common mistakes you’ve made in your program.