Blacklist entry

For some reason I am getting a ton of "DNR" spam from blackberry.net
with Subject: lines that imply that somebody here is the culprit.
(Hence this message here.)

I am blacklisting "blackberry.net" in an effort to reduce the spam load
here.

I figured it was just another case of something that *still* doesn't understand
the semantic difference between RFC821 MAIL FROM: and RFC822 From:

I'm comfortable with "....what stupidity is sufficient to explain."

I figure they are not bright enough to be malicious.