The term “blacklist” gives you either a kid image of a list that is colored dark black, or a list that functions the way the Schindler’s List does. You are wrong either way.
A blacklist is just a list of electronic mail addresses or domains that are quite known to be sending spam. If a certain email address or website is part of this list, then that means that particular email address or domain is blocked. By blocked, meaning no further mail or message can be received from them.
In the world today, many have learned the magic of the computer and are, thus, quite experts in avoiding any “cyber punishments”. In this case, having his or her email address or site blocked. Spammers, as they have already been given a name, learned certain methods on how to keep changing their return addresses to be able to foil the blacklists.
This is why blacklists are not usually utilized. They are more usually deceived, and thus they do not get to perform their purpose quite well. Spammers are becoming more and more talented and skilled each day, which makes blacklists less and less effective everyday as well.
It is a total waste of time...