title: Contact Form 7: use hook created using wpcf7_before_send_mail for only one contact form by id
body: <p>I am working on a site with several forms created using Contact Form 7.  For one of these forms, I am passing variables that I collected using a hidden input field in the form.  I am passing these variables into the email using the wpcf7_before_send_mail hook, but these values are passing into every email (I added dynamic variables as well as static text) Here's the code:</p>
  
  <pre><code>add_action( 'wpcf7_before_send_mail', 'wpcf7_add_text_to_mail_body' );
  
   function wpcf7_add_text_to_mail_body($contact_form){
       $values_list = $_POST['valsitems'];
       $values_str = implode(", ", $values_list);
  
       // get mail property
       $mail = $contact_form-&gt;prop( 'mail' ); // returns array 
  
       // add content to email body
       $mail['body'] .= 'INDUSTRIES SELECTED';
       $mail['body'] .= $values_list;
  
  
       // set mail property with changed value(s)
       $contact_form-&gt;set_properties( array( 'mail' =&gt; $mail ) );
  
   }
  </code></pre>
  
  <p>I am trying to figure out how to only pass these values to one of the contact form email templates, probably via the form id.</p>