This postbag account posting here above is spam. I am the maker and as I said you can just email us with a list of sites you want to exclude. Or, alternatively, by disallowing PostbagBot in your site's robots.txt.
Btw dawnerd, do you know how to flag a an account here? I tried and couldn't find it. Someone obviously registered with postbag handle to troll about Postbag as you've seen in the previous comment. I understand your frustration when you read such a comment. Rest assured that we would never refuse to exclude any site ever.