--On February 28, 2006 7:08:53 AM -0600 Al Lilianstrom 
<[log in to unmask]> wrote:

> Our advice to folks who are complaining about spamcop blocking our site
> has been to complain to their local mail admins about relying on spamcop
> for blocking mail. We use spamcop as part of a scoring system for spam
> that determine delivery but never rely on a single system (esp one we
> don't control) for blocking mail. I'm amazed that anyone does.

I use SCBL at home, and we also deploy it at my place of employ.  The false 
positive rate is *EXTREMELY* low.  We also use a 4xx (try later) rather 
than 5xx response code to the listings.  What this means is most transient 
problems just result in mail that's a little delayed, while the huge number 
of actual SPAM sources gets dropped right off before we have to process the 
message.  We block probably 40% of all attempted mail transactions using 
SCBL.  We're also starting to get more aggressive about blocking dynamic 
hosts.