I created a frontend submission which is integrated with a shortcode. After submitting the form the users are redirected to a thank you page which sends a mail to the admin of the website. Everything worked out well, but now we got some SPAM entries in the backend. These entries didn't send a mail to the admin, so I'm wondering if the form were submitted/ used by bots in a different way (e.g. the form is also visible or usable on other sites) and if it is possible to block bots (without recaptcha) - e.g. with honeypots.