Subject: [Asrg] More useless stats

From: "Eric Dean" <[email-masked]>
Date: Tue, 2 Sep 2003 16:39:13 -0400

In the past 10 days..one of our MX server has the following CR stats:
 
1)       45302: challenges sent out (new senders)
2)       1558: challenges respond with 550 SMTP reject code..results in
auto-blacklist
3)       696: confirmed responses to challenges
 
About 3% (1558) of the challenges are easily identified as bogus
senders.  The other 97% are either sent from a mail server that accepts
all email for the domain (using auto-gen username) or from a spammer
that really doesn't care about getting identified.  Yahoo, Aol and
others firewall at the user level and will not accept email destined for
a non-local user.  In fact, spammers are simply bold enough to use a
valid domain using valid return addresses.this somewhat obviates the
impact of RMX
 
Only 1.2% of challenges are responded to.  This doesn't necessarily mean
that users don't know what to do when challenged.there is no telling how
many of the 45,000 challenges were sent to non-spammers.  What is clear
is that additional methods are required.