title: Email verification regex failing on hyphens
body: <p>I'm attempting to verify email addresses using this regex: <code>^.*(?=.{8,})[\w.]+@[\w.]+[.][a-zA-Z0-9]+$</code></p>
  
  <p>It's accepting emails like <code>a-bc@def.com</code> but rejecting emails like <code>abc@de-f.com</code> (I'm using the tool at <a href="http://tools.netshiftmedia.com/regexlibrary/" rel="nofollow">http://tools.netshiftmedia.com/regexlibrary/</a> for testing).</p>
  
  <p>Can anybody explain why?</p>