Contact Email Dynamic add data to the email,
you can get data from custom html
Contact Form 7 uses hidden input type to store form id. It uses hidden field name _wpcf7. You can get the form Id like this way.
$form_id = $contact_form->posted_data['_wpcf7'];
So you final code should be
add_action( 'wpcf7_before_send_mail', 'wpcf7_add_text_to_mail_body' );
function wpcf7_add_text_to_mail_body($contact_form){
$form_id = $contact_form->posted_data['_wpcf7'];
if ($form_id == 123): // 123 => Your Form ID.
$values_list = $_POST['valsitems'];
$values_str = implode(", ", $values_list);
// get mail property
$mail = $contact_form->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->set_properties( array( 'mail' => $mail ) );
endif;
}