You don't have to send it through the filter. You can decide @ accept() time that the message will rejected. If you intended to blackhole it; you were plannin

You don't have to send it through the filter. You can decide @ accept() time that the message will rejected. If you intended to blackhole it; you were planning on burning bandwidth and letting the sender send their bytes entirely, and then responding "2xx OK, whatever" Instead, just simply say "500 FOAD." after DATA and be done with it on the non-zero chance the sender actually has something important to say, and needs to decide if they need to use another channel.