Email Validation Function

/**
 * emailValid
 * Email Validation Function
 * I take an email as a string and test it against 2 regular expressions.
 *
 * @author Regexp Author unknown
 * @author Phillip Harrington <[email protected]>
 * @param string $email
 * @return bool $valid
 */
function emailValid ($email)
{
  $valid = false;
  $email = trim($email);
 
  if(0 < strlen($email))
  {
    if(!preg_match('/(@.*@)|(\.\.)|(@\.)|(\.@)|(^\.)/i', $email))
    {
      if(preg_match('/^.+\@(\[?)[-a-zA-Z0-9\.]+\.([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$/i', $email))
      {
        $valid = true;
      }
    }
  }
 
  return $valid;
}