title: How do you do custom validation on FileHelpers?
body: <p>I want to throw an exception to say that we have an invalid email address as I dont want to proceed until we get a valid email address. Is this where I want to do it and if so, how?</p>
  
  <pre><code>void Engine_AfterReadRecord(EngineBase engine, FileHelpers.Events.AfterReadEventArgs&lt;UserInfoFromAd&gt; e){
       bool isEmailValid = IsEmailValid(e.Record.Email);
       if (!isEmailValid){
          //I want to throw exception
       }
   }
  </code></pre>