spammers started using techniques that avoid SpamCop reports against them:
1) Forged Received: lines pointing to IANA or some other clearly innocent party to which SpamCop doesn't want to send reports. Example:
Received: from vps.inteloc.com (vps.inteloc.com [::ffff:22.214.171.124])
by ums.usu.ru with esmtp; Thu, 09 Aug 2007 02:57:22 +0600
Received: from alsmwkb (126.96.36.199)
by vps.inteloc.com; Wed, 8 Aug 2007 13:57:24 -0700
Date: Wed, 8 Aug 2007 13:57:24 -0700
X-Mailer: The Bat! (v2.01)
X-Priority: 3 (Normal)
Subject: Our company offers you high earnings!
2) Delaying replies in order to avoid getting two spam reports. I.e., I replied to their "job offer" and got a link to h ttp://w ww.form-agr eement.co m/ (which is an attempt to get my credit card number) in two days (so that SpamCop considers the original mail to be stale).
1) Add a button in the "Report spam" page (that appears after clicking a link in the "SpamCop received X emails" message) to remove trust to a certain Received: line.
2) Add a button to paste related (but stale) email that is known to be from the same user, in order for it to be parsed for abuse addresses. The "Additional information" box doesn't work for this purpose because it doesn't do this parsing.