public class Mail  {

public Mail() {
    _host = "smtp.gmail.com"; // default smtp server
    _port = "587"; // default smtp port587

    _user = "myname@gmail.com"; // username
    _pass = "password"; // password
    _from = "myname@gmail.com"; // email sent from
    _to = {"yourname@gmail.com"};
    _subject = "go"; // email subject
    _body = "mail"; // email body

    _debuggable = true; // debug mode on or off - default off
    _auth = true; // smtp authentication - default on

    _multipart = new MimeMultipart();

    // There is something wrong with MailCap, javamail can not find a handler for the multipart/mixed part, so this bit needs to be added.
    MailcapCommandMap mc = (MailcapCommandMap) CommandMap.getDefaultCommandMap();
    mc.addMailcap("text/html;; x-java-content-handler=com.sun.mail.handlers.text_html");
    mc.addMailcap("text/xml;; x-java-content-handler=com.sun.mail.handlers.text_xml");
    mc.addMailcap("text/plain;; x-java-content-handler=com.sun.mail.handlers.text_plain");
    mc.addMailcap("multipart/*;; x-java-content-handler=com.sun.mail.handlers.multipart_mixed");
    mc.addMailcap("message/rfc822;; x-java-content-handler=com.sun.mail.handlers.message_rfc822");
    CommandMap.setDefaultCommandMap(mc);
}

public Mail(String user, String pass) {
    this();

    _user = user;
    _pass = pass;
}

public boolean send() throws Exception {
    Properties props = _setProperties();

    if(!_user.equals("") && !_pass.equals("") && _to.length > 0 && !_from.equals("") && !_subject.equals("") && !_body.equals("")) {

       Session session = Session.getInstance(props, new GMailAuthenticator(_user,_pass));

        MimeMessage msg = new MimeMessage(session);

        msg.setFrom(new InternetAddress(_from));

        InternetAddress[] addressTo = new InternetAddress[_to.length];
        for (int i = 0; i < _to.length; i++) {
            addressTo[i] = new InternetAddress(_to[i]);
        }
        msg.setRecipients(MimeMessage.RecipientType.TO, addressTo);
        msg.setSubject(_subject);
        msg.setSentDate(new Date());

        // setup message body
        BodyPart messageBodyPart = new MimeBodyPart();
        messageBodyPart.setText(_body);
        _multipart.addBodyPart(messageBodyPart);

        // Put parts in message
        msg.setContent(_multipart);

        // send email

        Transport t = session.getTransport("smtp");
        try {
            t.connect(_host, _user, _pass);
           t.sendMessage(msg, msg.getAllRecipients());

        } finally {
            t.close();
        }


        return true;
    } else {
        return false;
    }
}

private Properties _setProperties() {
    Properties props = new Properties();

    props.put("mail.smtp.host", _host);

    if(_debuggable) {
        props.put("mail.debug", "true");
    }

    if(_auth) {
        props.put("mail.smtp.auth", "true");
    }

    props.put("mail.smtp.port", _port);
    props.put("mail.smtp.starttls.enable", "true");
    props.put("mail.debug", "true");

    return props;
}


// class for secure access gmail

class GMailAuthenticator extends Authenticator {
    String user;
    String pw;
    public GMailAuthenticator (String username, String password)
    {
        super();
        this.user = username;
        this.pw = password;
    }
    public PasswordAuthentication getPasswordAuthentication()
    {
        return new PasswordAuthentication(user, pw);
    }
}

final Button send = (Button) this.findViewById(R.id.send);
    send.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            // TODO Auto-generated method stub

           new SendClass().execute();

    }
    });

private class SendClass extends AsyncTask{

    @Override
    protected Object doInBackground(Object[] objects) {
        Mail m = new Mail();

       m.send();
        return null;
    }
}