Spambot honeypot

Out of the blue, we started getting a ton of spam signups.

Using Optin Monster for static and lightbox popup hover forms.

I don't want to force double opt-in, not that that would solve the problem anyway, but is there a simple way to enable a Honeypot that will automatically reject the spam sign up?

I read this thread: [link] https://sendy.co/forum/discussion/161/lots-of-spam-signups-on-double-opt-in-list/p1

And this post: [link] http://nfriedly.com/techblog/2009/11/how-to-build-a-spam-free-contact-forms-without-captchas/

I've got this input into OptinMonster:



<?php     <form action="http://aircargo.io/subscribe" method="POST" accept-charset="utf-8">
<?php   <input type="text" name="name" id="name" placeholder="Name" />
<?php   <input type="hidden" name="list" value="J01CXkwd389285AYGgS8WepQ"/>

 <?php               <p class="antispam">Leave this empty:

<?php   <input type="submit" name="signup" id="signup" value="Submit!" />
<?php     </form> >

(without all of the) php at the beginning obviously. I don't know how to get the form to show in Markdown. and this in the CSS:

html div#om-cviyby1pq9-lightbox .antispam { display:none;}

However, I'm not sure what to do with this to edit it properly and put it in subscribe.php:

<?php
// if the url field is empty
if(isset($_POST['url']) && $_POST['url'] == ''){
     // then send the form to your email
          mail( 'you@yoursite.com', 'Contact Form', print_r($_POST,true) );
}
// otherwise, let the spammer think that they got their message through
?>

Thanks

We'll get back to you as soon as possible

I assume all I need to do is get that edited and input into subscribe.php to stop the spambots.

Can you tell me how to edit it please, because we've got a 4mb attachment going with each autoresponder email and they're signing up by the hundreds per day?