Send mail in javax.mail without authentication
private void createSession() {
properties.put("mail.smtp.auth", "false");
//Put below to false, if no https is needed
properties.put("mail.smtp.starttls.enable", "true");
properties.put("mail.smtp.host", server);
properties.put("mail.smtp.port", port);
session = Session.getInstance(properties);
}
I think, this would suffice.