Spam Harassment Reduction via Economic Disincentives (SHRED) is a proposed sender-at-risk E-mail stamp mechanism for reducing the E-mail spamming problem by indirectly increasing the cost of E-mail sending to the senders of unwanted E-mail. It aims to avoid the defects in earlier sender-at-risk mechanisms. The main aim of SHRED is to provide economic incentives for legitimate ISPs to clean up the botnet problem within their networks, by making it cheaper to do so than to continue to pay excess p… (More on Shred)