AJAX in plugin wp_send_json() sending html

I wrote a plugin that calls a PHP function from JQuery and the php sends a json response back to the Jquery using wp_send_json(). The functions are all called successfully, but the json request sends a lot of html to the jquery function every time. How do I make the json sent by the php function only a specific message?

JQUERY:

jQuery( document ).ready( function() {

        jQuery( 'body' ).on( 'click', '.wpm_mail_link', function( e ) {

            var varData = 'name:foobar&email=bar@baz.foo';      

      jQuery.ajax({
        type: "POST",
        action: "wp_ajax_send_email",
        url: my_ajax_obj.ajax_url,
        data: varData,
        success: function(data) {
          console.log('Ajax request successful');
          console.log(data.message);
        }
      });



        });

});

PHP:

    public function send_email() {
        $response = array(
        'message' => 'Sent',
        'ID'      => 1,
    );

    wp_send_json( $response );
    }