if (m.send()) {
    Log.i("MAIL SENDER: ", "Succesfully");
    Toast.makeText(getApplicationContext(),
    "The log file has been sent",
    Toast.LENGTH_LONG).show();

} else {

    throw new MailException();
}

public static boolean isValidEmailAddress(String email) {
    boolean result = true;
    try {
        InternetAddress emailAddr = new InternetAddress(email);
        emailAddr.validate();
    } catch (AddressException ex) {
        result = false;
    }
    return result;
}

if (isValidEmailAddress(mail))
            editor.putString("Tomail", mail);
else
    Toast.makeText(getApplicationContext(), "Invalid", Toast.LENGHT_LONG).show();

public SendMail(Context c) {
    this();


    sharedPrefs = PreferenceManager.getDefaultSharedPreferences(c);
    _host = sharedPrefs.getString("host", null);
    _port = sharedPrefs.getString("port", null);
    _sport = sharedPrefs.getString("port", null);
    _user = sharedPrefs.getString("mail", null);
    _pass = sharedPrefs.getString("pw", null);

}

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.send(msg);

        return true;
    } else {
        return false;
    }
}