title: When Benchmarking my code, this one regex multiples the runtime of a loop by 4
body: <p>The offending regex is</p>
  
  <pre><code>TldCheck = new Regex(@"(live|lycos|mail|yahoo|gmail|msn|netzero|peoplepc|sbcglobal|verizon|hotmail|earthlink|cox|bellsouth|comcast|barracuda|att|aol)\.?(com|net|org)@", RegexOptions.IgnoreCase | RegexOptions.Compiled);
  </code></pre>
  
  <p>When it's run against the list, it causes some major lag. Is there anyway to rewrite this? The purpose it clear email lists of emails like:</p>
  
  <pre><code>adsfyahoocom@aol.com
  adsfyahoocom@comcast.net
  adfadyahoocom@gmail.com
  </code></pre>