original_string: function email($str,$mx=TRUE) {
  		$hosts=array();
  		return is_string(filter_var($str,FILTER_VALIDATE_EMAIL)) &&
  			(!$mx || getmxrr(substr($str,strrpos($str,'@')+1),$hosts));
  	}
code: function email($str,$mx=TRUE) {
  		$hosts=array();
  		return is_string(filter_var($str,FILTER_VALIDATE_EMAIL)) &&
  			(!$mx || getmxrr(substr($str,strrpos($str,'@')+1),$hosts));
  	}
code_tokens: function email ( $ str , $ mx = TRUE ) { $ hosts = array ( ) ; return is_string ( filter_var ( $ str , FILTER_VALIDATE_EMAIL ) ) && ( ! $ mx || getmxrr ( substr ( $ str , strrpos ( $ str , '@' ) + 1 ) , $ hosts ) ) ; }
docstring: Return TRUE if string is a valid e-mail address;
  Check DNS MX records if specified
  @return bool
  @param $str string
  @param $mx boolean
docstring_tokens: Return TRUE if string is a valid e - mail address ; Check DNS MX records if specified