Initially, when I released spamcopuri I decided to pretty much ignore whether the TLD was a country code or not. This results in about twice as many queries as necessary, but guaranteed you would get hits if the domain was listed.
Now that people are pointing this to other RBL's beside just surbl, should we continue to do second and third level queries? Or just the query that we assume to be necessary? My concern is that not all RBLs will process the domains according to a list such as http://www.bestregistrar.com/help/ccTLD.htm. I suppose the worst case scenario is we end up getting a miss when we should be getting a hit because one side presumes that say TLD .za has a subdomain 'foo', when the server doesn't. The server side would expect a second level, while the client would do a third level query (this is why I wanted the wildcard records). I guess this really isn't that great a consequence considering the savings and the fact that this shouldn't occur very often.
I will go ahead and make this change if everyone is comfortable with the known risk.
thanks,
--eric