I try to send e-mail for java but I get run time error

From:

sahm <sahm007@gmail.com>

Newsgroups:

comp.lang.java.programmer

Date:

Tue, 18 Oct 2011 03:12:39 -0700 (PDT)

Message-ID:

<e8f0b81a-c1ad-41ad-8447-0a44f339e33f@v15g2000vbm.googlegroups.com>

Hi Every One

I tried to send e-mail for java code using Apache Commends Mail
library 1.2
and below is my code
====================Start===================
package netscan;

import org.apache.commons.mail.SimpleEmail;
import org.apache.commons.mail.EmailException;
import org.apache.commons.mail.*;

/**
*
* @author salim
*/
public class SendMail {

    public static void sendEmail()
    {
        System.out.println("Function is Colled");
        try
        {

        SimpleEmail email = new SimpleEmail();
        System.out.println("Email Opject is Created");
        email.setHostName("mail.Hostname.com");
        System.out.println("Host Name was Set");
        //email.setAuthentication("my e-mail", "my Password");
        email.setAuthenticator(new DefaultAuthenticator("my e-
mail","my password"));
        email.setDebug(false);
        //email.setDebug(true);
        email.setSmtpPort(26);

        email.addTo("receiver e-mail");

        email.setFrom("my e-mail", "me");
        email.setSubject("JAVA Test message");
        email.setMsg("This is a simple test of commons-email");
        email.send();

        //return;
        }
        catch(EmailException ex)
        {
            System.out.println(ex.toString());
        }
    }

}
===================End====================

and there is no error in compaile time but in run time I get this
error

==========================================
Exception in thread "main" java.lang.NoClassDefFoundError: javax/mail/
Message
    at netscan.SendMail.sendEmail(SendMail.java:31)
    at netscan.NetScan.main(NetScan.java:104)
Caused by: java.lang.ClassNotFoundException: javax.mail.Message
    at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
    ... 2 more
Java Result: 1
BUILD SUCCESSFUL (total time: 0 seconds)
==========================================

I need your help

Best
Salim