Searches DNS for records of type type corresponding to host .
A common use of this function is to check the validity of an email address. The above code appears to run flawlessly, although when put to the test there appears to be a hole in it. I realize that this is probably unnecessary due to the fact that such a domain wouldn't pass the initial rational expression in the above example. Apparantly, you forgot that an email address can begin with an underscore. This function is not available in windows 2000 as of this date.