My b2evolution Version: Not Entered

I want my blog readers to be able to subscribe for e-mail notifications without having to register. In version 1.10 I had my own little "hack" for this, but I can't get it to work any more.

I had just made a php-file of my own and modified edit_actions.php

// post post-publishing operations:
		if( $edited_Item->status != 'published' )
		{
			echo "<div class=\"panelinfo\">\n";
			echo '<p>', T_('Post not publicly published: skipping trackback...'), "</p>\n";
			echo "</div>\n";
		}
		else
		{ // trackback now:
			trackbacks( $post_trackbacks, $edited_Item->content, $edited_Item->title, $edited_Item->ID);
			
      // Elsas subscription:
  		require "sendSubscriptions.php";
      
      $msg = notifySubscribers($Blog->ID,$edited_Item->get_permanent_url());
  		echo '<div class="panelinfo"><h3>Sending e-mail to subscribers for blog ID ' . $Blog->ID . "</h3><p>" . T_($msg) . "</p></div>";	
  		
  		if ($Blog->ID == "3")
  		{
    		insertIntoStormvarningNews($edited_Item->get_permanent_url(), $edited_Item->title);
    		
    		echo '<div class="panelinfo"><h3>Updating Stormvarning news</h3><p></p></div>';
      }	
		}

But now I cannot even seem to find the file to modify... What should I do?

On this site
http://blogs.lib.berkeley.edu/dmtechtraining.php/2008/02/14/bspace_research_tools

they use feedburner to take care of e-mail subscriptions. I've been trying to figure out how they do it, but I can't. Can anyone help me?