Enough of this thread. Really. Spamcop is risky if used for outright rejection. This is not new information, and as pointed out, Spamcop themselves say so. The subject line is pure ignorance, "abusing mail systems," absurd.
Reliance on email where you do not control both ends is also risky. We can all look at what some other site does, and say, "I wouldn't do that." Maybe to some extent it is useful to share our reasons for feeling that way, although it's not fully on topic here. But we do not have the right to judge them: it's their server, their rules. And getting all angry about what rules they choose is nothing short of STUPID, as is the defensive reaction over being criticized for the choices you have made. Take it off list. -- Offlist mail to this address is discarded unless "/dev/rob0" or "not-spam" is in Subject: header