Email email = new SimpleEmail();
String authuser = "......@gmail.com";
String authpwd = "*******";
// Very Important, Don't use email.setAuthentication()
email.setSmtpPort(587);
email.setAuthenticator(new DefaultAuthenticator(authuser, authpwd));
email.setDebug(true); // true if you want to debug
email.setHostName("smtp.gmail.com");
email.getMailSession().getProperties().put("mail.smtp.auth", "true");
email.getMailSession().getProperties().put("mail.debug", "true");
email.getMailSession().getProperties().put("mail.smtp.port", "587");
email.getMailSession().getProperties().put("mail.smtp.socketFactory.port", "587");
email.getMailSession().getProperties().put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
email.getMailSession().getProperties().put("mail.smtp.socketFactory.fallback", "false");
email.getMailSession().getProperties().put("mail.smtp.starttls.enable", "true");
email.setFrom("........@gmail.com", "SenderName");
email.setSubject("TestMail");
email.setMsg("This is a test mail?");
email.addTo(".............@gmail.com", "ToName");
email.setTLS(true);
email.send();