On October 13th, the MT-Blacklist plugin was released by Jay Allen. However, I found that the Blacklist.pm conflicts with the Adam Kalsey comment notification Hack.
There is a simple way of fixing this small error if you do not want to receive e-mails of your comments. It worked for me but I can't guarantee it will work for you. If you try it, make sure you back up the original files you are modifying before attempting. I don't suggest this to novice MT users.
Open Blacklist.pm to line 2395 and you will see the following:
MT::Mail->send(\%head, $body);
Place the following code in its place:
MT::Mail->send(\%head, $body) unless $author->email eq $comment->email;
This will act the same as the Adam Kalsey Comment notification Hack as Patricia posted in reply to the original entry posted on the hack.